Atsuatsutchi is light red with chubby cheeks and a tuft of fur on his forehead. There is a red heart on the back of his head, and it makes Atsuatsutchi appear to have two small ears.
In the Anime
Atsuatsutchi is depicted as being very shy in the anime. However, he is a very big fan of Lovelin and gets excited when he has a chance to meet her. He also has a Lovelin doll. He has a crush on Himetchi and sometimes fights with Sabusabutchi to win her heart.
Atsuatsu is a Japanese term that can mean "passionately in love", which may refer to the heart on his head and his love for Himetchi. However, atsu can also mean "hot", which may be derived from the fact that his rival's name, sabu, means "cold".