Story
"I'm going to take revenge on them." Yuusuke Midorikawa, a high school boy, has a girlfriend named Kayo Yoshioka, who was his childhood friend. After many years, he confessed his long-standing feelings for her and they officially became lovers; but it seems she's becoming estranged from him lately. One day, while he worried over these age-appropriate problems, he witnesses Kayo and another boy who seems to have hit it off with her, leaving a karaoke place by themselves.
Synopsis via AniList (English).
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