Yorokobi to Shiawase to

 is a musical composition from the Nichijou soundtrack. It was used in scenes in which Nano feels an overwhelming feeling of sentimental happiness (as opposed to the more upbeat, fun-having happiness of Ukiuki Happiness): Episode 13 (untitled scene in which Hakase tells Nano she gets to go to school tomorrow); Episode 14, Part 56 (Nano tries on her uniform at home); and Episode 26, Part 110 (Hakase surprises Nano before school by removing her key).