Sei and Honoka met each other thanks to introductions from friends. The two fell in love at first sight and have been dating for two years. The two also decided to live together and Sei even became engaged to Honoka. Honoka also loves Sei very much, she also wants to have children with him soon. But there is one thing Sei has always hidden from Honoka. That's... Sei is someone who likes to be "NTR"! Even though he tried to keep this secret in his heart, every time Sei realized that he loved Honoka and was loved by her, that feeling grew stronger. Sei finally made a choice, deciding to tell Honoka the truth and invite senior Hosoda to fuck his girlfriend! At first Honoka felt this was ridiculous and unacceptable, but because she loved Sei so much, she agreed to let him be happy. And then, Sei invited senior Hosoda to his house to drink, then he would excuse himself and leave the two of them alone. Sei also secretly installed a camera to monitor everything. And it happened exactly as Sei wanted. Hosoda quickly invaded Honoka's body. Although she repeatedly refused, she did not resist his actions. Even though Sei let someone else take over his girlfriend's body, he still doesn't want to lose Honoka and still wants her to be his girlfriend. But this did not happen the way Sei wanted. Hosoda's cock was both big and hard and could penetrate places that Sei had never explored, making Honoka climax in pleasure over and over again. She gradually became dependent on him, couldn't leave him, went to live at his house for many days, and didn't even need to contact Sei. When he went to his senior's house and witnessed Honoka lustfully having sex with Hosoda right before his eyes without any hesitation, Sei knew that perhaps he had really lost her...