The Pout-Pout Fish
This book sends absolutely the wrong message, in more ways than one. Basically, the main character is upset, and the only thing his "friends" tell him is that he should smile for them, oblivious to the possibility that he might have a legitimate problem of some kind, or that feeling sad is even okay in this aquatic world. They don't want to deal with his feelings. Then a stranger arrives and kisses him on the face, which magically fixes the problem, suggesting to impressionable kids (as other reviewers here have pointed out) that going around kissing people you don't know is acceptable and in fact desirable. My video review goes into more detail.