On Valentine's Day, after the two neighbors eat dinner together as usual, Mahiru gives Amane some hot chocolate. Amane accepts it as a normal Valentine's Day gift, but Mahiru seems restless, as if she has something to tell him. When Mahiru rushes home, still unable to say what's on her mind, Amane notices a small bag with a card at his front door. Inside the bag are chocolates that Mahiru made especially for Amane, who had said that he doesn't like very sweet things. In return, Amane gives Mahiru a special present on White Day.

The day before spring break, Itsuki has a fight with his father and asks Amane to let him stay over. When Chitose finds out that her boyfriend will get to enjoy Mahiru's cooking, she demands to join them and stay at Mahiru's apartment. The four friends spend the next few lively days together. After Itsuki and Chitose leave, Amane returns home one day to find Mahiru confronted by her mother, Sayo. Noticing Mahiru's dark expression and sensing that something is wrong, Amane invites Mahiru in. The two sit together on Amane's sofa as Mahiru timidly explains her complicated history with her parents.

When the new school term starts, Amane and Mahiru are put in the same class. At home, Amane makes meal requests and gives Mahiru gifts. The two neighbors' relationship is almost as intimate as if they were married. At school, however, Amane treats Mahiru like a stranger. When Mahiru notices how differently Amane treats Itsuki and Chitose, she gets the uncomfortable feeling that she is being left out. Mahiru tries to think of a way to gradually get closer to Amane.

"Amane-kun, I want to go shopping with you during Golden week." Amane accepts Mahiru's invitation and the two get dressed up to go out on a secret date. The neighbors talk, hold hands, and fully enjoy their special day out on the town. When stopping for a break, they coincidentally bump into Yuta, who quickly puts two and two together. The next day, Itsuki and Yuta grill their buddy Amane about whether or not he has feelings for Mahiru. Amane starts to feel the pressure from his friends' sharp questions.

Amane explains the reason he left home in middle school and began living alone. Mahiru empathizes with his sorrow and embraces him. "At least let me spoil you a little." The next day, Mahiru's classmates ask her about the boy she was seen walking with. Mahiru nonchalantly admits that it was a date, surprising Amane. Mahiru then confesses, "there's no one more dear to me in life than him."

Amane's studying pays off and he reaches sixth place with his midterm exam scores. Mahiru had promised to do anything he asked if he reached the top ten, and Amane somewhat reluctantly ends up laying in her lap again. Mahiru smiles at Amane as he eventually gives in and falls asleep at her hands. Not long after, Mahiru also falls asleep. When Amane wakes up and has to carry the half-asleep Mahiru back to her own room, she unwittingly invites him to sleep next to her in bed.

While Amane realized that Mahiru had feelings for him, his past experiences left him without the confidence to move forward with her. On school sports day, the two end up participating in the scavenger race event together. When Mahiru finds out the item she has to search for, she grabs Amane's hand and heads for the goal, surprising Amane. Then, in front of their stunned classmates, Mahiru courageously announces that Amane is dear to her. In that moment, Amane makes up his mind to confess his feelings.