My Fake Little Brother Is Such a Tease, What Should I Do?

He moved into a new home with his mother after she remarried.

There, he met the “older sister” who was his sister in name only.

She had protected him since they were little, always standing up for him.

All he could do was quietly follow behind her.

When would his sister realize how he felt about her?

She was an academic ace, but her biological father brought home a “little brother” who was both weak and terrible at school,

always sighing about life.

Oh well, he was her brother, so she’d just have to spoil him herself.

But what’s with him lately?

Why does he keep looking at her so strangely?