The MC is very naive in the beginning, but the author mentions that it is deliberate since the MC grew up extremely sheltered (and is also not reincarnated/transmigrated or anything). He also wants to marry only his Master and Senior Sister, but the Author makes a Note that it is definitely going to be a harem - which makes sense, as the MCs Yin-Yang Saint Body makes dual cultivation extremely fast (both for him and his partners).