Grand Blue Dreaming

The manga is published in English by Kodansha USA under the Kodansha Comics imprint. An anime television series adaptation by Zero-G aired from July to September 2018. A live-action film adaptation was released in August 2020. A second anime season by Zero-G and Liber aired from July to September 2025. A third season by Zero-G and Saber Works premiered in July 2026.

It is recorded as the work of Kenji Inoue. Publication is recorded by Kodansha and Kodansha USA Publishing, LLC. The recorded date of publication is 2014. It is associated with Japan. Recorded genres are comedy anime and manga and slice of life anime and manga. The recorded subject matter is scuba diving.

Iori Kitahara looks forward to his new life on the Izu Peninsula as he prepares to start his college life there, staying in a room above his uncle's diving shop "Grand Blue." However, he is quickly shocked as he meets the local Diving Club, a group full of buff men who spend more time drinking, partying, and stripping naked than actually diving. Despite his attempts to distance himself from the group, Iori gets quickly swept up in their antics, while his cousins try to show him the wonders of diving into the ocean and sea.

Iori Kitahara (北原 伊織, Kitahara Iori) Voiced by: Yuma Uchida Portrayed by: Ryo Ryusei (live-action film) Iori is a first-year Mechanical Engineering student at Izu University and a member of the diving club, despite never having learned to swim. Though he attempts to live an ordinary life, he frequently finds himself drawn into the club’s chaotic activities, which often involve drunken antics. Outwardly brash and carefree, he deeply values his relationships and suppresses his flaws when necessary. Despite his father’s adoption into the Kotegawa family, he considers Chisa and Nanaka as true siblings. His genuine demeanor gradually endears him to others, though his earlier immaturity sometimes causes friction. Once an aspiring musician, he now cringes at his past attempts at songwriting. Naturally athletic, he excels in sports requiring precision, though he tends to overcomplicate simple problems with absurd theories. He occasionally cross-dresses. Chisa Kotegawa (古手川 千紗, Kotegawa Chisa) Voiced by: Chika Anzai Portrayed by: Yūki Yoda (live-action film) Chisa is Iori’s cousin and classmate at Izu University, a composed and intelligent young woman devoted to diving. Unlike the other members of the Peek a Boo club, she maintains a reserved demeanor, avoiding their rowdy behavior and showing little interest in romance. Despite her disinterest, she frequently deflects advances from fellow students. Aspiring to become a dive instructor like her mother, she prioritizes diving above all else. To maintain her independence, she manipulates situations—even pretending to be in a relationship with Iori to deter suitors or retaliate when he helps others over her. Though she shares a love of diving with Iori, their dynamic shifts between warmth and frustration due to his loud personality. Her strained relationship with her mother leaves her emotionally guarded, causing her to become flustered in vulnerable moments. Kōhei Imamura (今村 耕平, Imamura Kōhei) Voiced by: Ryōhei Kimura Portrayed by: Atsuhiro Inukai (live-action film) Kōhei is Iori’s best friend and rival, an eccentric otaku who proudly wears anime-themed shirts. He enrolls at the university chasing an unrealistic dream of attracting high school girls, but is instead drawn into the Peek a Boo club. His obsession with anime distorts his social awareness, often leading him to misinterpret real-life situations through the lens of his favorite shows. Easily manipulated by references to famous female voice actors—especially Kaya Mizuki—he becomes a frequent target of the club’s pranks. Despite his absurd demeanor, he demonstrates unexpected resolve when his interests are threatened. Though his friendship with Iori is marked by playful antagonism and boisterous clashes, he remains deeply loyal when it counts. Hints suggest he hails from a wealthy background. Aina Yoshiwara (吉原 愛菜, Yoshiwara Aina) Voiced by: Kana Asumi Portrayed by: Ren Ishikawa (live-action film) Aina is a shy Ōmi Women’s College freshman who joins Peek a Boo after Iori and Kōhei defend her from bullying at her former tennis club. Nicknamed "Cakey" for her heavy makeup, she sheds this persona upon joining, revealing a timid nature that contrasts with the club's rowdiness. Though initially interested in Kōhei, she develops feelings for Iori after he avenges her. Her farm upbringing makes her adept at manual labor but self-conscious about her rural accent. Naive about romance and insecure about her body compared to Nanaka and Azusa, she paradoxically becomes wildly uninhibited when drinking. Ryūjirō Kotobuki (寿 竜次郎, Kotobuki Ryūjirō) Voiced by: Katsuyuki Konishi Portrayed by: Hiroaki Iwanaga (live-action film) A senior student at Izu and a member of Peek a Boo who often got himself and other club members drunk and naked. Kotobuki is just like Tokita both in appearance and in personality when they are partying, but Kotobuki can be surprisingly charismatic. He works as a professional bartender part-time. Shinji Tokita (時田 信治, Tokita Shinji) Voiced by: Hiroki Yasumoto Portrayed by: Suzunosuke Tanaka (live-action film) A senior student at Izu and member of Peek a Boo who often got himself and other club members drunk and naked, Tokita is a muscular, laid-back college student who loves to party. However, just like the other members of PAB, he sincerely loves diving and takes the possible dangers seriously. To Iori's surprise, he has a girlfriend. Azusa Hamaoka (浜岡 梓, Hamaoka Azusa) Voiced by: Toa Yukinari Portrayed by: Yuka Ogura (live-action film) Azusa is a senior at Ōmi Women's College and one of the few female members in Peek a Boo's senior circle. Her natural sensuality leads younger members to assume she is sexually experienced, though her interests focus almost exclusively on Nanaka for comedic effect. While harboring unrequited feelings for Tokita, she avoids acting on them to preserve group harmony. Notoriously unconcerned with modesty, she frequently undresses without warning. She befriends Iori after mistakenly believing him to be bisexual, seeing him as a potential confidant. Despite her playful mischief that often creates humorous complications, she demonstrates genuine care and insight when helping others with personal problems. Karina Leader of the German Weeb Club.

Nanaka Kotegawa (古手川 奈々華, Kotegawa Nanaka) Voiced by: Maaya Uchida Portrayed by: Aya Asahina (live-action film) Nanaka is a diving instructor at Grand Blue and Chisa's older sister. A voluptuous yet reserved figure, she typically observes rather than participates in the diving club's rowdy activities. Her presence alone causes the members to moderate their usual drunken behavior. She states she would support Iori if he could make her sister happy. Ironically naive about sexual matters, she frequently finds herself in compromising situations with Iori and Azusa. She demonstrates terrifying physical strength when perceiving any threat to her bond with Chisa. Toshio Kotegawa (古手川 登志夫, Kotegawa Toshio) Voiced by: Shinji Kawada Portrayed by: Masahiro Takashima (live-action film) The owner of the diving shop Grand Blue and Iori's uncle, as well as the father of Chisa and Nanaka. Kaya Mizuki (水木 カヤ, Mizuki Kaya) Voiced by: Nana Mizuki A famous voice actor and idol who is acquainted with Peek a Boo on account of her diving hobby. She is friends with Azusa and thinks highly of Iori. She is Kōhei's favorite voice actress.

Captain Kudō (工藤会長, Kudō-kaichō) Voiced by: Jun Fukuyama Portrayed by: Yuya Hirata (live-action film) The Captain of the Tennis Club, "Tinkerbell," and an attractive playboy who was publicly humiliated by Iori and Kōhei due to his mistreatment of Aina. Hajime Nojima (野島 元, Nojima Hajime) Voiced by: Takuya Eguchi Portrayed by: Yūki Morinaga (live-action film) One of Iori's classmates at Izu University. A self-styled playboy who is largely unsuccessful in attracting a lover. Although he tries to be charismatic, it usually comes off as lame. Shinichirō Yamamoto (山本 信一郎, Yamamoto Shin'ichirō) Voiced by: Junya Enoki Portrayed by: Yūma Yamoto (live-action film) One of Iori's classmates at Izu University. Incredibly blunt in his desire to find a girlfriend, he is often teased by his friends that he will be a lifelong virgin. Kenta Fujiwara (藤原 健太, Fujiwara Kenta) Voiced by: Robert Waterman One of Iori's classmates at Izu University. A muscular man, and the most decent and innocent of Iori's friends. He is often portrayed as invisible to other significant characters as a running joke. Yū Mitarai (御手洗 優, Mitarai Yū) Voiced by: Natsuki Hanae One of Iori's classmates at Izu University. Unlike most of the others, Yu is in a relationship with his childhood friend Rie, which his friends immediately attempt to sabotage once they find out. Through a self-destructive desire to flirt or his friends' machinations, he finds himself beaten up by Rie on multiple occasions. Shiori Kitahara (北原 栞, Kitahara Shiori) Voiced by: Sumire Morohoshi Iori's little sister, a third-year middle school student who often walks around in an old-fashioned kimono. She pretends to show affection to Iori while secretly trying to mold him into taking ownership of their family's ryokan so she will not have to, as she seeks to escape the stringent demands placed upon her by her parents. Shiori is unusually cunning and intelligent for her age, able to construct surveillance equipment as well as maintain a facade as an impeccably mannered young girl who dotes on her brother. She later develops genuine respect for Iori, although she still dismisses him as dim-witted and irresponsible. Naomi Otoya (乙矢 尚海, Otoya Naomi) Voiced by: Yoshino Aoyama Iori's co-worker, and a high-school student. He is passionate about diving and is the president of the diving club at his school. He secretly likes Iori. Sakurako Busujima (毒島 桜子, Busujima Sakurako) Voiced by: Aya Yamane A student at Oumi Women's University. She is focused on good looks, both for herself and her partners. Sayaka Kotegawa (古手川紗耶華, Kotegawa Sayaka) Voiced by: Sayaka Ohara Chief (チーフ, Chīfu) Voiced by: Asami Seto Maki (マキ) Voiced by: Aya Suzaki

Written by Kenji Inoue and illustrated by Kimitake Yoshioka, Grand Blue Dreaming started in Kodansha's seinen manga magazine Good! Afternoon on April 7, 2014. Kodansha has compiled its chapters into individual tankōbon volumes. The first volume was released on November 7, 2014. As of April 2026, 26 volumes have been released. Kodansha USA is publishing the series in both digital and print format, with 23 volumes published as of December 2, 2025.

An anime television series adaptation was announced in March 2018. It is produced by Zero-G, directed and written by Shinji Takamatsu, with Takamatsu also handling sound direction, and Hideoki Kusama designing the characters. The series aired from July 14 to September 29, 2018, on the Animeism programming block on MBS, TBS and BS-TBS, as well as other networks. The opening theme song is "Grand Blue", performed by Shōnan no Kaze, while the ending theme song is "Konpeki no al Fine" (紺碧のアル・フィーネ), performed by Izu no Kaze (a group formed by Yūma Uchida, Ryohei Kimura, Hiroki Yasumoto, and Katsuyuki Konishi). The first season was streamed exclusively on Amazon Prime Video worldwide. In September 2024, a second season was announced, with Takamatsu returning as director and scriptwriter, and Liber joining Zero-G for animation production. The season aired from July 8 to September 23, 2025, on Tokyo MX and other networks. The opening theme song is Seishun Towa (青春永遠; 'Eternal Youth'), performed by Shōnan no Kaze featuring Atarashii Gakko!, while the ending theme song is "Hadaka de Dotsukiai" (裸でどつきあい; 'Let's Punch Each Other While Naked'), performed by Seamo featuring May'n. Crunchyroll is streaming the second season. Tropics Entertainment licensed the series in Southeast Asia for streaming on Tropics Anime Asia YouTube channel. After the airing of the final episode of the second season, a third season was announced. It takes place in fictional Palau. The season is produced by Zero-G and Saber Works, with Takamatsu returning as director. It premiered on July 7, 2026. The opening theme song is "Natsuko" (夏子), performed by Funky Monkey Babys, while the ending theme song is "Hadaka no Mermaid" (裸のマーメード; 'Naked Mermaid'), performed by Mameshiba no Taigun.