My First Girlfriend is a Gal

Hashiba Junichi, a high school student determined to lose his virginity, is pressured by his friends to ask out classmate Yame Yukana. After humiliatingly begging her on his knees, he is insulted as a freak, but an unexpected turn of events changes everything.

Junichi begins dating Yukana after a heartfelt confession, much to the envy of his friends. Yukana takes him to a karaoke bar after school, leading his friends to speculate about the couple's future.

Junichi discovers a love letter in his shoe box and, despite having a girlfriend, feels obligated to politely decline the sender's advances. Just as another girl begins to grow close to him, Yukana arrives at an inconvenient time, complicating the situation.

Junichi spends lunch with Yukana in the courtyard, but Ranko's presence disrupts their time together. Kashii Yui, a reserved and formal girl, approaches Junichi and later invites him to a cafe after school, where she inquires about the nature of his relationship with Yukana. Junichi expresses his happiness with Yukana, though complications may lie ahead.

Junichi wakes up in a strange situation, finding himself with a large-breasted girl on top of him, whom he does not recognize. He is confused and startled by the unexpected encounter and her use of exaggerated, flirtatious speech. The situation appears to have originated from a dream in which he was with Yukana.

Junichi grows closer to Yukana with Shinpei's encouragement, who suggests playing the King Game to further their relationship. They gather at Yukana's home, where her casual appearance catches Junichi off guard, deepening the tension between them just as the moment begins to escalate.

The gang plans a summer beach vacation and Junichi takes a job at a cosplay café to save money. Coincidentally, Yukana, Ranko, Yui, and Nene are also working there, though Junichi is assigned to the kitchen while the girls interact with customers. The café's manager exhibits some unusual behavior.

Junichi and Yukana, along with their friends, spend a day at the beach, where Junichi attempts to prevent his companions from engaging in inappropriate behavior by peeking at women who are not properly clothed.

Junichi becomes suspicious and confronts Yukana after witnessing her speaking with Dai, a man other than himself. Their conversation leads to an argument as tensions rise between them.

Junichi confronts Dai after he makes a disrespectful comment toward Yukana, leading to a physical altercation. Afterward, Junichi and Yukana have a conversation that helps them reconcile and move past the conflict.