Sawa (沢) means "swamp". Yoritsugu (頼継) means "trust/request" and "inherit/succeed/patch/graft".
Yoritsugu Sawa has a very easygoing personality. When Rakan and his mother fell into his garden, he wasn't suspicious of them at all, and even adopted them.
He saw Rakan as the grandson he never had and gave Rakan his name.
He regarded Rakan's mother as the daughter he never had.