Kotaro, a boy of four with an unusual air about him, arrived at Shimizu Apartment entirely alone. He appeared to have no family or guardians in the wider world.

Karino understands the source of Kotaro’s peculiar speech. He’s mimicking Tonosaman, the character from his favorite television program, a show nearing its conclusion.

Kotaro's eyes light up at the sight of someone distributing free balloons, and he makes a determined effort to gather as many as possible. There’s a particular purpose behind his collecting.

Kotaro’s friend Kakeru lived a life meticulously managed by a devoted maid, who anticipated and fulfilled every need. Observing this, Kotaro resolved to demonstrate to Kakeru the satisfaction of self-sufficiency, showing him how to manage h…

Kotaro possesses an unusual fastidiousness when it comes to tissues. He insists on the finest, softest kind, describing them as "sweet." It is later revealed to Karino the reason behind this preference.

Aota took up residence in the building for a month's stay. His request for friendship from Kotaro stirred something within Karino – a flicker of suspicion, tinged with a hint of jealousy.

Each afternoon, following the end of school, Kana began visiting Kotaro’s home. Yet, despite the shared space, a quiet melancholy seemed to cling to her, and she rarely appeared genuinely happy.

Karino took Kotaro and his companions to the cinema. Kotaro was eager to see the latest Tonosaman picture, but his friends had their hearts set on a different film.

Each time Kotaro visits the neighborhood dentist, Dr. Ohba makes a point of speaking with him, engaging him with questions.

A woman, unfamiliar to Kotaro, arrived to collect him from kindergarten that afternoon. She identified herself as Karino’s former girlfriend.