The movie follows a 4-year old boy who is struggling to cope with the arrival of a little sister in the family, until things turn magical. A mysterious garden in the backyard of the boy's home becomes a gateway allowing the child to travel back in time and encounter his mother as a little girl and his great-grandfather as a young man. These fantasy-filled adventures allow the child to change his perspective and help him become the big brother he was meant to be. 聊聊《未来的未来》片中的住宅设计。大家对细田守监督还真是温柔啊。细田守家族观的隽永对望。难以为继的私人影像。导演，咱能请个编剧吗？。不像是催生片，更像是一个二胎家长的反思。细田守结婚之后大概过得很幸福吧…。适合成人看的动画。细田守的雕刻时光。《未来的未来》：每个人都曾经是孩子，曾经年轻过。 在东京的宁静角落，生活着幸福的三口之家。而今，这户人家迎来了新生命。爱撒娇的儿子小君，迎来刚出生的妹妹，他感到父母对自己的爱被妹妹夺走，正在恼怒之时，小君却在庭院中遇到来自“未来”的妹妹，并开启了穿越之旅，在家族之树的时空中，他和“未来”的妹妹一起，与童年的母亲、年轻时代的曾外祖父、甚至未来的自己相遇，在冒险中，小君领悟到不同形式的“家族之爱”。
