Why Is My Strict Boss Melted by Me?

Average company worker Shimono spends his days constantly being helped and scolded by his superior and section chief Kamijou Touka. One day, he finds himself having traveled back in time to his high school years. He sees this as a chance to aggressively approach the section chief a second time around, only to find out that very woman had turned into a girl constantly acting lovey-dovey towards him! Turns out that she also time leaped back in time to the same point as Shimono. She was under the impression that she was the only one who traveled back in time, deciding to act as lovey-dovey and close with Shimono, who she actually had feelings for at the time. Through this leap in time begins a romantic story depicting this mutually unrequited love!