It's really unique story line , two water spirits who lives in river met a kid and tht kid father also met them , and all the stuffs goes on but later on that river going to be in under-construction so both of them goes away as soon as kid gets to know about it he tells those water spirits about it , and then they went somewhere else they will never get old though it's not even yaoi or shounen ai but just there is strong attachment between characters.
Tsuki to Mizu no Yoru