Responses
well art styles don't just appear, you have to develop them. so they either have the exact same taste in style (which i doubt, since it's pretty unique) or they decided to have the same.(more likely, especially since it's normal to work as assistant and help others first, so they probably worked together too)
for one moment i've said wawwww a new work for OGAWA Chise and then !!!!!
maybe it's her new pen name or her twin sister :)