Koikimo

An anime television series adaptation produced by Nomad premiered on March 29, 2021, on streaming platforms and on television from April 5 to June 21, 2021.

Ryo Amakusa is a successful but womanizing businessman, and Ichika Arima, a high school girl, is best friends with his younger sister. Ichika saves Ryo from falling down a staircase on a rainy day, and she later encounters him again at his home while visiting his sister. He attempts to repay her with flirtatious advances, only to be harshly rejected. Shocked by her blunt disgust, Ryo unexpectedly falls in love with her. From then on, Ryo persistently pursues Ichika with overly direct confessions and grand romantic gestures, while Ichika continues to respond with insults and irritation. Despite her reactions, Ryo sincerely tries to change himself and prove his feelings are genuine.

Ichika Arima (有馬一花, Arima Ichika) Voiced by: Yurie Kozakai A 16 year old high school student who, after saving Ryo from falling down the stairs and giving him her lunch, ends up receiving Ryo's enthusiastic approaches. Her name means "one flower" and probably because of this, Ryo sends her one flower a day to her house as a way to prove his feelings. While rejecting Ryo everytime he approaches her, Ichika doesn't seem to mind Ryo's presence. Ryo Amakusa (天草亮, Amakusa Ryō) Voiced by: Toshiyuki Toyonaga A 26 year old womanizer salaryman who falls in love with Ichika after receiving a cold reply from her when offering his own body as gratitude for saving him. Rio Amakusa (天草理緒, Amakusa Rio) Voiced by: Rena Hasegawa Ryo's younger sister and Ichika's best friend and classmate who is supportive of her brother's feelings. Kai Tamaru (多丸快, Tamaru Kai) Voiced by: Junya Enoki Ichika's classmate who develops feelings for her. Arie Matsushima (松島有枝, Matsushima Arie) Voiced by: Kana Hanazawa Ryo's colleague at work who has feelings for him. Masuda (益田, Masuda) Voiced by: Ryōhei Kimura Ryo's best friend since middle school and he is a photographer.

The series is written and illustrated by Mogusu. It was first uploaded on Pixiv until it got an online manga serialization on Ichijinsha's Comic Pool digital manga magazine in January 2015. Eight tankōbon volumes were released between January 2015 and March 2021.

An anime television series adaptation was announced by Ichijinsha on January 21, 2020. The series is animated by Nomad and directed by Naomi Nakayama, with Taku Yamada serving as assistant director. Yūko Kakihara overseeing scripts, Mariko Fujita designed the characters and serve as chief animation director, and Hiroaki Tsutsumi composed the music. The series aired from April 5 to June 21, 2021, on AT-X, Tokyo MX, UHB, MRT, GTV, GYT, and BS Fuji. The series premiered on March 29, 2021, on streaming platforms. Ace Collection performed the series' opening theme song "Monoqlo City", while MaRuRi to Ryuga performed the series' ending theme song "Linaria". Crunchyroll licensed the series outside of Southeast Asia.

A stage play adaptation of the manga was announced in February 2024. It is scheduled to run in Tokyo from April 26–May 5, and in Osaka from May 10–12, 2024. The play will be directed and written by Naohiro Ise. The cast includes Yuna Shibata as Ichika Arima, Hiroki Uchi as Ryō Amakusa, Yayoi Tatsumoto as Rio Amakusa, Mizuki Chiba as Masuda, Ryōki Nagae as Kai Tamaru, and Chiaki Omigawa as Arie Matsushima.