Hatsuinu

Hatsuinu (初犬) 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.

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

Not impressed by Fukaya's libido, she runs off and meets Mita, a girl who has a crush on Fukaya. Mita gives Fujino a potion that she said will improve Fujino and Fukaya's sex life warning her not to drink it. Curious about the contents of the potion, she drinks it. The potion increased Fujino's sexual desire. In an attempt to rid herself off the effects of the potion, Fujino takes Fukaya into a school bathroom and tells him to repeatedly have sex with her. He does so until she faints. Fukaya takes Fujino to the school nurse. He meets Mita in the hallway and questions her about why Fujino would be so sexually active. In response, Mita kisses Fukaya, her lips laced with the potion. With his libido increased, he takes Mita home, where she forces herself on him. Meanwhile, Fujino wakes up at the nurse's office and asks the nurse where Fukaya is. She tells Fujino that she last saw him with Mita. Fearing for Fukaya, she runs to his house to find Mita and Fukaya having sex. Disgusted, Fujino runs out of the house, with Fukaya chasing after her. Fukaya explains the situation to her and have make-up sex in an alleyway.

One day, Fukaya falls down on his head, causing memory loss. Mita 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. The girls compromise on their feelings to Fukaya and both of them pleasure him at the same time. The school nurse reminiscences on her affair with a teacher in her past and masturbates in her office. Fukaya enters the office, asking the school nurse for help, thinking and deciding that she is his girlfriend from before the accident and has sex with her on the spot. The nurse explains that she is not his girlfriend and beats him up for it. The whole incident was watched by Fujino.

Manga
Hatsuinu is written and illustrated by Inu. Issuisya has released the 23 chapters of the manga into three tankōbon volumes between April 22, 2006 and July 11, 2008.

OVAs
Hatsuinu The Animation (初犬 The Animation) was released as two original video animation episodes on their individual DVDs by Pink Pineapple between March 25, 2007 and July 27, 2007. This OVA is about how Fukuya becomes Fujino's boyfriend and how he fears that she values her vibrator more than him even though they have passionate sex. To solve the problem, Fukaya takes Fujino to a swimming pool, where she cannot use her vibrator. However, Fujino is revealed to have a waterproof vibrator with her.

The sequel, Hatsuinu 2 The Animation - Strange Kind of Womans ~again~ (初犬 2 The Animation ストレンジ・カインド オブ ウーマンズ ～again～) is another two-episode original video animation. Pink Pineapple released the OVAs on separate DVDs between September 26, 2008 and December 26, 2008. .