2 Bodys, 1 Person

Both of them are siblings, and to be specific they are twin, with both of them have different gender, a male and a female.

They grow up with each other, they never had any intention to get involves with anyone. They are twin, but things getting weird.

Both of them have same mindsets, same behavior and same personality. As if they were only one person instead of two, it's terrifying to get close with them.