A good portion of this sequence - several scenes up to 0:14 - looks like Eiichi Nakamura's animation to me. The distinctive-looking multiples, and for that matter the characters' facial expressions and even the timing (he used ones very often, at times even moreso than Kobayashi), are quite reminiscent of his later work on Ganso Tensai Bakabon (and, by extension, Doraemon), as is the more appealingly stylized, geometric yet solid way in which the characters are drawn - see the scenes in which Ikasama deals with the two brown mice from 0:11 to 0:14, in particular, for a good example of all these characteristics.