Board Thread:Episode Discussions/@comment-25787298-20160519120227/@comment-3568954-20160519124917

Hagoromo having the Sharingan first is logical. his mother has the Rinne Sharingan which is a superior sharingan but it doesn't have the same power as the Rinnegan. its logical that he would have the sharingan first. she has a single Rinne Sharingan he inherited the Sharingan but over both eyes then after learning sage mode his eyes evolved into the Rinnegan this is pretty logical

also it seems that the toads live in an underground cave system similar to how the otsutsuki lived on the moon.