I have interests in parental care and sexual conflicts over reproduction in teleost fishes. My goal is to understand social relationship among individuals by approaching the field researches and observations in lab conditions, from evorutionary views. In the resent years, I also conduct some field works to examine a composition of food-webs in aquatic ecosystem and evaluate the relationships between biodiversity of aquatic animals (e.g. dragonflies) and their local and landscape habitats.