Ujioka Tasuku is a tall first-year high school student, standing at 192 cm with a prominent scar on his face. Because of his intimidating appearance, he is constantly misunderstood as frightening, leading to a lonely school life with no friends. Determined to change this and finally enjoy his youth, he arrives at school on the first day with high hopes. His plan takes an unexpected turn when he witnesses a girl named Shimohoshizaki Kodzuru trip and fall over a banana peel. Despite her clumsy and spacey demeanor, Ujioka is moved by her earnest hardworking nature. More importantly, she is the first person who does not judge him by his looks. Touched by this, the two lonely beginners decide to become friends and navigate the trials of adolescence together.

The story follows their awkward yet sincere efforts to build a connection, focusing on the realistic and often messy process of two outcasts learning to trust. However, contrary to typical romantic comedy narratives, their relationship does not follow a destined or straightforward path. The manga explores how the bond between Ujioka and Shimohoshizaki, while meaningful, proves to be temporary. Their romance is brief and does not succeed, but the personal growth gained from the experience leaves a lasting impact. The title reflects this bittersweet reality: a spring shared with someone who was kind in some ways but ultimately cruel in others, bringing both warmth and pain.

As the narrative progresses, it becomes clear that the relationship is not meant to last forever. The story deliberately avoids exaggerated drama or prolonged misunderstandings common to the genre, instead presenting an ordinary and human portrayal of young love that simply runs its course. After their time together ends, both characters take the lessons and confidence they gained from each other to move forward. Ujioka learns to open up to others, finding the courage to make new friends and eventually try again with someone new. The final message reflects on the transient nature of relationships, acknowledging that people enter and leave our lives for simple reasons, but the strength and memories gained from those encounters remain. The manga concludes on a note of quiet hope, likening the arrival of new opportunities to the certainty that spring will come again next year.