Dera is a bird that speaks Japanese, with a little bossy tone, that ends up staying at Tamako's house. He is a noble attendant for a royal court from a tropical island and was on journey to find a bride for its prince. However, after gaining an affinity for mochi, he has put on a lot of weight and thus cannot fly properly anymore, only being able to manage short distances before he runs out of breath. He is often just referred to as "Bird" by Tamako's family, or simply "Dera-chan" by Tamako, as his surname sounds very similar to "mochi mazui" , lit. bad tasting mochi). Dera maintains that he is rather versed in the ways of love, sometimes giving Mochizō and Midori love advice on their respective crushes on Tamako. Dera is rather full of himself as well, which usually stems from a series of misunderstandings. He believes anyone that sneezes in his direction is in love with him, he himself having a crush on Shiori. His body contains a communication system used by the prince to communicate with him, although it only works when Dera is unconscious, thus he has no memories of any time the prince attempts to contact him. In his unconscious state, he can also be hooked up to video devices and used like a projector.
Source from Wikipeida