A Marriage Guide with My Paladin Sister

His older sister, the captain of the Holy Knights, turns out to be a yandere who dotes on her little brother to an extreme?

"Xiao Yi, you can only belong to me!"

The second personality living inside his mind is a white-haired fox girl?

"My other half~ Mm! Don't touch my tail!"

How is someone reincarnated into a different world like this supposed to keep a low profile and survive?