Shōhei is a retired high school principal and head librarian who lives with his wife, Shōko. They have three grown daughters. Shōhei suffers from advancing dementia: he mixes up words, gets lost and wanders off, confuses memories, and constantly loses his dentures. But his last decade is filled with warmth and humor, and even as his own memory disappears, the family rediscovers the love and trust he has for them.