Dictionary / Vocabulary / 血縁
けつえん · also けちえん
blood relationship; consanguinity; blood relative
common word
正直なところ、その当時の僕は血縁がどうとか、続柄がどうとか、そういう話はまるで理解出来ちゃいなかった。
Truthfully, at that time, I didn't have the first idea about such talk: family links, blood relations or whatever.