Manyū Hiken-chō

• Ja Kanji — 魔乳秘剣帖 • Ja Romaji — Manyū Hiken-chō • Genre — * Action • Comedy • Historical

• Type — manga • Author — Hideki Yamada • Publisher — Enterbrain • Imprint — Techgian Style • Magazine — Tech Gian • First — July 21, 2005 • Last — November 21, 2011 • Volumes — 7

• Type — tv series • Director — Hiraku Kaneko • Producer — * Akira Matsui • Hiroaki Ooki • Yoshiyuki Ito • Writer — Seishi Minakami • Music — Miyu Nakamura • Studio — Hoods Entertainment • Licensee — Crunchyroll • Network — TV Kanagawa, Tokyo MX, Chiba TV, KBS Kyoto, Sun Television, AT-X • First — July 11, 2011 • Last — September 26, 2011 • Episodes — 12 + 8 OVAs

• Portal — yes The Secret Scroll of the Magic Breast Sword is a Japanese manga series written and illustrated by Hideki Yamada. It was published in Enterbrain's bishōjo game magazine Tech Gian from July 2005 to November 2011, with its chapters collected in seven tankōbon volumes. Set in a parallel version of the Taihei Edo period, the series follows Chifusa, a busty kunoichi learning to be samurai. A 12-episode anime television series adaptation, produced by Hoods Entertainment, aired from July to September 2011.

In a land ruled by the Tokugawa shogunate, big breasts mean everything. Those women who have huge breasts are guaranteed wealth and popularity. The women who lack them are not considered "human". Members of the ruling Manyū clan help raise future big-breasted women. Written on a secret scroll possessed by the clan, there are said to be various techniques on how to grow big and beautiful breasts. Chifusa is to be the successor of the clan. However, she takes the secret scroll and runs away with it, hoping to fight against the cruel world that the Manyū clan has created.

• Chifusa Manyū • Eri Kitamura (Drama CD), Minako Kotobuki (anime) • Chifusa is the successor of the Manyū clan, a skilled samurai known for her hotheaded and impulsive nature. Despite her temper, she is deeply loyal and kind-hearted. Due to her upbringing, she often finds herself distracted by buxom women, a weakness exploited by her pursuers. Rejecting her clan's tradition of judging women by breast size, she abandons her family and steals the Scroll of Secrets, which contains techniques for breast enlargement. She masters the Chichi-nagare, a unique ability to manipulate breast size, though initially, she can only absorb others' breast mass. Determined to master this technique, she seeks to ensure all women in Japan have equal opportunity, opposing the societal favoritism toward large breasts and their exploitation. • Kaede • Ryō Hirohashi (Drama CD), Aki Toyosaki (anime) • Kaede is Chifusa's lifelong friend and devoted attendant, having abandoned the Manyū clan alongside her. Though technically subordinate, she frequently takes charge, particularly in managing finances or restraining Chifusa's impulsive tendencies. Her deep loyalty borders on possessiveness, as she often reacts with jealousy when others show interest in Chifusa. She openly admires Chifusa's physique, leading many to assume they share a romantic relationship. While her feelings are never explicitly confirmed, her behavior suggests an attachment beyond mere friendship. • Ouka Sayama • Mamiko Noto • Ouka is a skilled assassin and swordswoman sent by the Manyū clan to capture Chifusa. Cold and merciless in combat, her abilities equal or surpass Chifusa's. Their conflict began in youth when Chifusa first accidentally used the Breast Flow technique on her during a duel, leaving Ouka flat-chested. After suffering the harsh treatment reserved for small-breasted women, she found refuge under Muneyuki, who disregarded societal prejudice against her. This act inspires her fierce devotion to him, suggesting deeper feelings. Her personal vendetta against Chifusa drives her relentless pursuit. • Kagefusa Manyū • Yumi Tōma (Drama CD), Kaoru Mizuhara (anime) • Kagefusa is Chifusa's sadistic older sister and a master of the teppo. A staunch supporter of the Manyū clan's traditions, she resents Chifusa for being chosen as successor despite having a smaller bust. Their conflict escalates when Chifusa accidentally uses the Breast Flow technique on her, stealing her breasts and forcing her to rely on an inflating bra. Initially consumed by vengeance, Kagefusa eventually relents after Chifusa vows to restore her bust once mastering the technique. This reconciliation softens her outlook, making her more easygoing, though she retains her cruel streak. • Muneyuki Manyū • Kenji Hamada • Chifusa's brother, whom she initially admires greatly. He is the chief Manyū Breast Inspector because of his great, natural ability to analyze them. It is because of this job that he despises large breasts, since he claims that after years of staring and analyzing them he has grown tired of them. After Chifusa's defection, his darker side comes up, revealing that he is as ruthless as his father and is willing to go to brutal lengths to preserve Manyū rule. It is implied that he is either in love with or holds certain feelings for Ouka. • Kokage • Misato Fukuen • Kagefusa's assistant and best friend. Very much like what Kaede is to Chifusa, Kokage is eternally loyal to Kagefusa, even though Kagefusa is a lot sterner to Kokage than Chifusa is to Kaede. Kokage is very inexperienced in combat and commonly acts as a spy and reconnaissance agent for Kagefusa, looking for information to track down Chifusa and Kaede's location. • Munenori Manyū • Hidekatsu Shibata (Drama CD), Atsushi Ono (anime) • The lord of the Manyū clan, the ruler of Japan and Chifusa's father. He is the leader of the Manyū. He preserves the Manyū's system of rule, in which a woman's worth is judged on by the size of her breasts, through a totalitarian demeanour of government. He is shown to be very cold and vengeful, issuing a death warrant for his own daughter because of her defection and spares no expense to have her stopped. • Kyoka Manyū • Ayahi Takagaki • Chifusa's kind-hearted older sister. She is the most calm person of her family and despite her general mercy and good nature, she still is an enemy to Chifusa after her defection. • Hatomune Mie • Chō (Drama CD), Tōru Ōkawa (anime) • Mie is a feudal lord who first encounters Chifusa while judging a risqué contest she enters to repay an innkeeper's kindness. After accidentally seeing her bare breasts, he becomes fixated on touching them, abandoning his position to search for her. When they later reunite, he aids Kaede in rescuing Chifusa from a rival lord's palace. Though offered the chance to fondle Chifusa's breasts as a reward, he respectfully declines, demonstrating personal growth. He ultimately returns to his duties as lord, his obsession tempered by newfound maturity. • Ame Shuji • An assassin for the Manyū clan who was sent to assassinate Chifusa and retrieve the scroll from her possession. She invited a traveling Chifusa to her home where she attempted to steal the scroll but was caught by Chifusa, resulting in a duel between the two of them where Chifusa held her own initially, until Ame revealed her skill by secreting blinding liquid from her nipples at Chifusa's eyes.

Written and illustrated by Hideki Yamada, Manyu Scroll was first published as a one-shot in Enterbrain's bishōjo game magazine Tech Gian on July 21, 2005. The manga was eventually serialized in the magazine and finished on November 21, 2011. Enterbrain collected its chapters in seven tankōbon volumes, released from March 24, 2007, to January 25, 2012.

A drama CD produced by Chara-Ani was released on October 16, 2010.

An internet radio show, entitled Manyū Hiken-chō: Oedo Radio, aired on Onsen (Internet radio) from July 4 to October 24, 2011. The show was hosted by Tōru Ōkawa and Mamiko Noto, the respective voices for Hatomune Mie and Ouka Sayama.

A 12-episode anime television series adaptation was produced by Hoods Entertainment, directed by Hiraku Kaneko, with series composition by Seishi Minakami, music composed by Miyu Nakamura, character designs by Jun Takagi, and produced by Akira Matsui, Hiroaki Ooki, and Yoshiyuki Ito. The series' opening theme is "Fate" and the ending theme is "Futatsu no Ashiato", both performed by Airi. The series was broadcast on TV Kanagawa and other networks, including Tokyo MX, Chiba TV, KBS Kyoto, Sun Television, and AT-X, from July 11 to September 26, 2011. An uncensored "Director's Cut" version was streamed on the ShowTime's video portal service. The episodes were collected on four DVD and Blu-ray sets, released from October 4, 2011, to January 7, 2012; each volume included a short original video animation (OVA) titled Binyū Tanren-hō Nyū-Togi, and a picture drama titled Kaede no Chifusa-sama Oppai Seichō Kiroku. Crunchyroll began streaming the series, 13 years after the original broadcast, on January 16, 2024.