Don'yorinnu has a blob-by appearance, for her body has the form of a jelly, purple in color, with her "hair" having a lighter tone, with a hairband with a small bow on the left side to match. She has very short arms, slightly puffy lips and round eyes with the eyelashes pointing downwards.

Don'yoriinu is an amicable individual with a passive disposition to match. In the anime, after having an argument with her husband Honoboono, she tries to find him to make amends, implying she can be easily forgiving. She is more noble than she appears, as she feels guilty for nearly driving Keita's parents' relationship into an abrupt end.

In the anime, she seems to enjoy shopping and having vacations, both of them shared with Honoboono.

She has a verbal tic of some sort, as she always ends her statements with "-juban" in Japanese, and "no filter" in the English dub.

Don'yoriinu has an aura capable of disturbing the emotional atmosphere of a place, causing people to hold arguments. If happening near married couples, it could inflict serious disputes over trivial matters and, if not taken care, spark a divorce. This effect is cancelled by Honoboono's own aura.