Beloved wife drowning in pleasure crazy alive with others stick

The main character, Kazumi Tsukayama, has his beloved wife, Waso Tsukayama.
when i was in college, i belonged to a circle for the purpose of spear, and kazumi who was playing with a woman、
After meeting Waso, he stopped playing in circles and playing with women, and continued to love only her.

however, a few years have passed since i married waso, and i was living a happy life、
I see the news that the circle I once belonged to was causing sexual trouble to several women in a group.
Kazumi, who had already become estranged from the circle at that time, was afraid of what he would think if his wife knew about his past.

One day, Toshio, who was a acquaintance of the university days, appears before Kazumi who had been living such a day、
While telling Kazumi that he knew that he belonged to that circle, he handed him a USB memory stick.
What was shown in the file there was a figure of the old Waso and Toshio hugging each other.
When questioned, Toshio admits that he had been dating Waso in the past.
When the man appears before him, he resents the fact that he has taken Waso and thinks that he has come for revenge, and he is wary.
And around Kazumi, something was gradually changing ....

主人公・塚山一巳には、愛する妻・塚山和奏がいた。
大学時代にはヤリ目的のサークルに所属し女と遊びまくっていた一巳も、
和奏と出会ってからはサークルも女遊びもやめ、彼女だけを愛し続けた。

しかし和奏と結婚してから数年が経ち幸せな生活を送っていたところ、
かつて所属していたサークルが集団で幾人もの女性に対し性関係のトラブルを起こしていたというニュースを目にする。
その当時すでにサークルとは疎遠になっていた一巳だが、自分のそんな過去を妻に知られてしまったら何と思われるのかと恐れを抱いていた。

そんな日々を送っていたある日、一巳の前に大学時代の顔見知りであった登志男が現われ、
一巳があのサークルに所属していたことを知っていると告げながら、一枚のUSBメモリを手渡してくる。
そこにあったファイルに映されていたのは、昔の和奏と登志男が抱き合う姿だった。
問い詰めると、登志男は昔和奏とつきあっていたことを認める。
今その男が自分の前に現われたことは、和奏を奪ったことを恨み、復讐のために来たのだと思い警戒する。
そして、一巳の周りでは、何かが徐々に変わっていた――。