It's called a 'episode'. Blathers, Pelly and PHyllis, Able and Sable all have one. At certain times of the year the characters will open up to you and tell you about themselves and you will gradualy build of their friendship. Able and Sable will tell you how their parents died. I think blathers tell you how he tries to overcome his insect fears. I have no idea what pelly and phyllis tell you.
Just talk to him every day

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