That's rather difficult unless you give me something more specific. There are a lot of "happy" anime but most of them are also borderline annoying.Originally Posted by Archangel
Aishiteru ze Baby is a very happy/cute drama story about a highschool student taking care of his 5 year old cousin who was left alone. The main character is somewhat of a playboy so it's quite funny to see him suddenly try to assume the role of a parent.
Watching any animated version of manga written by the great Adachi Mitsuru always leave me smiling so therefore, I recommend the following:
Touch The story revolve around a pair of twin brothers who both have feeling for their childhood friend. The older twin is a slob while the younger is the hero of the school but their childhood friend treat them both equally. It's a drama with a heavy baseball background.
H2 Story involving 2 main characters who are best friends and rivals in both love and baseball. One of the main character suffered an injury that forced him to quit baseball so he enrolled in a highschool that does not have a baseball team but eventually circumstances eventually bring him back into the game.
I know the description of the Adachi works sound really plain but it's really hard for me to give a much better description since i don't want to spoil story elements that get reveal early on. Both anime were from the 80's so they looks outdated but they come with my highest recommendation. Both have their fair share of comedy and tend to come across as funny without being forced and the story is well paced and contain enough twist to keep them interesting.
All of those anime are quite happy so you won't feel depressed watching them.