Dwelling on past fame as a once-celebrated author of a single novel, Ryota (Hiroshi Abe) struggles to find his footing in life. He squanders his modest earnings as a private detective on gambling, leaving him unable to support himself or provide child support for his son. To make quick cash, Ryota resorts to offering his detective services to clients or even blackmailing them. Although he's presented with an opportunity to write for a manga series alongside an emerging artist, his pride holds him back from pursuing this new venture.
In the midst of his personal struggles, Ryota grapples with the recent loss of his father, while his elderly mother, Yoshiko (Kirin Kiki), seems to embrace a new chapter in life. Engaging in activities with a group of local elderly ladies, she appears to be moving forward. However, Ryota becomes suspicious of his sister Chinatsu's frequent visits, fearing that she is trying to take advantage of their mother. This concern grows when he discovers that Yoshiko intends to use her social pension to finance her granddaughter's figure skating lessons. Meanwhile, Chinatsu harbors suspicions about Ryota's intentions, recalling a secret hiding spot where their mother once concealed money from their gambling father. When Ryota later investigates this old hiding place, he is momentarily pleased to think he has uncovered cash, only to be disappointed when he finds only cardboard and a note from his sister.
Amidst family tensions, Ryota yearns to reconcile with his ex-wife Kyoko (Yoko Maki), who has grown weary of his empty promises regarding child support payments. She threatens to limit his time with their young son Shingo ([Taiyo Yoshizawa]), a situation that worries Ryota as he knows Kyoko has moved on and may even remarry, possibly severing his connection with Shingo. During a tumultuous summer storm, Ryota finds himself with his family at his mother’s home. It is here that Kyoko delivers the crushing news that their time together is truly over, emphasizing that adult life requires more than just love—it demands planning and responsibility, traits Ryota has not demonstrated in the past. This conversation sparks a realization in Ryota: he must reclaim control over his life if he wishes to play a significant role in Shingo's.
Determined to forge a deeper bond with his son, Ryota seizes the chance to recreate a cherished memory from his own childhood, seeking refuge from the storm in a local playground, much like he did with his father years ago. The following morning, the storm fades, but the journey of self-discovery and familial reconnection continues as they go about their lives with renewed hope and commitment.
