Kanojo ni Uwakisareteita Ore ga, Koakuma na Kouhai ni Natsukareteimasu
I Was Cheated on by My Girlfriend but My Devilish Junior Now Yearns for Me / Kanojo ni Uwaki Sareteita Ore ga / Koakuma na Kouhai ni Natsukareteimasu / My Coquettish Junior Attaches Herself to Me! / カノジョに浮気されていた俺が、小悪魔な後輩に懐かれています,

After his girlfriend cheats on him, Hasegawa Yūta is single just weeks before Christmas. A casual conversation with his female friend, Mino Ayaka, leads into an unexpected encounter on a street full of couples. There, Yūta meets Shinohara Mayu, a charming young woman dressed in a Santa suit. He wonders whether this meeting with Mayu could become his Christmas present.