Hatsu Ino the Animation

Hatsuinu (初犬, lit. "First Dog") is a Japanese manga written and illustrated by Inu about a series of short hentai stories but "The Strange Kind of Woman" story continues throughout the three volumes. Issuisya has released the 22 chapters of the manga into three bound volumes between April 22, 2006 and July 11, 2008. The manga was adapted into two original video animation series, named Hatsuinu The Animation and Hatsuinu 2 The Animation - Strange Kind of Womans ~again~, respectively. 

 

 

While on a train during Tokyo rush hour, high school student Fukaya Mamaru finds himself crushed against his classmate, the silent Fujino Shion (藤乃紫音). Unknown to Mamaru, Shion has a vibrator in her vagina, which increased its intensity when Mamaru pushed himself against her. Unable to turn off the vibrator discreetly, Shion endures the train ride while requesting Mamaru to satisfy her sexual cravings, to which he complies. After they get off the train, Shion gives Mamaru a remote control for her vibrator as a thank you gift. After the incident, Shion meets Mamaru to satisfy her sexual needs. 

 

Not impressed by Mamaru's libido, she runs off and meets Mita Yuki, a girl who has a crush on Mamaru. Yuki gives Shion a potion that she says will improve Shion and Mamaru's sex life warning her not to drink it. Curious about the contents of the potion, Shion drinks it. The potion increases Shion's sexual desire. In an attempt to rid herself off the effects of the potion, Shion takes Mamaru into a school bathroom and tells him to repeatedly have sex with her (Shoin's plea for sexual relief is the first and only time when she verbally speaks to him). He does so until she faints. Mamaru takes Shion to the school nurse. He meets Yuki in the hallway and questions her about why Shion would be so sexually active. In response, Yuki feeds him the potion via a kiss. With his libido increased, he takes Yuki home, where she forces herself on him. Meanwhile, Shion wakes up at the nurse's office and wants to know where Mamaru is. The nurse tells Shion that she last saw him with Yuki. Fearing for Mamaru, she runs to his house to find Yuki and Mamaru having sex. Disgusted, Shion runs out of the house, with Mamaru chasing after her. Mamaru explains the situation to her, and they have make-up sex in an alleyway. 

One day after getting caught in a fight between Shion and Yuki, Mamaru falls down on his head, causing memory loss. Yuki takes advantage of the situation and calls herself his girlfriend. He has sex with both of them and is still confused as to which girl is his girlfriend. Later, a teacher who broke the school doctor's heart when she was a student returns and offers Yuki a love potion to best Shion and win Mamaru ... and the price is only Yuki's body!