Hatsuinu

Plot

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!

Manga

Hatsuinu is written and illustrated by Inu. Issuisya released the 23 chapters of the manga into three tankōbon volumes between April 22, 2006 and July 11, 2008. On April 26, 2010 the manga was re-released as a two volume kanzenban edition called Strange Kind of Woman (ストレンジ・カインドオブウーマン). This version only includes the Strange Kind of Woman stories, i.e. it is missing chapters 1 and 5–9 from volume 1 of Hatsuinu. Eros Comix released an English version of the kanzenban edition as A Strange Kind of Woman, with translations by Toren Smith and Studio Proteus. The first volume was published on November 29, 2011 and the second was released on September 2, 2014.

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 Mamaru becomes Shion's boyfriend and how he fears that she values her vibrator more than him even though they have passionate sex. To solve the problem, Mamaru takes Shion 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.