リゾート開発に伴う立ち退きで、賛否の意見が真っ二つに割れた小向家。家の中では喧嘩が絶えず、居ても立っても居られなくなったリコ(与田祐希)は家の蔵へと逃げ出す。そこで見つけたのは、祖父・仁(森下能幸)が残したとあるプラモデルだった…！
やっさん(田中要次)から、そのプラモデルは祖父が現世に想いを託した“遺プラ”だと聞いたリコは、家族全員でプラモデルを作ろうと提案する。果たして、プラモデル作りを通じてバラバラになった家族の心は一つに戻るのか…小向家のひと夏の物語、ここに完結――
The Komukai family is split down the middle with those in favor and against being evicted due to the development of a resort. There are constant fights in the house, and Riko (Yoda Yuki), unable to sit still any longer, runs away to the family storehouse. There she finds a certain plastic model left behind by her grandfather Jin (Morishita Yoshiyuki)...! When Riko hears from Yassan (Tanaka Yoji) that the plastic model is a "legacy" of her grandfather's feelings for this world, she suggests that the whole family get together to make a plastic model. Will the family's broken hearts be reunited through the making of plastic models? This is the conclusion of the Komukai family's summer story.
