oにいniiさんsan
1.

A term of respect used by younger siblings when addressing or referring to their older brother, conveying both familiarity and honor.

2.

A word used to refer to a young man in a polite or friendly manner, often used by children or younger individuals when directing attention to a male in a casual context.

3.

A respectful way to refer to someone who holds an older brother's position, applicable in various contexts, such as familial or social interactions, indicating care or affection.

4.

A casual yet respectful term that can be used to address a male in a service or community role, reflecting both politeness and a sense of camaraderie.

Example:

彼のお兄さんは有名なサッカーの選手です。

ぎり義理giriのおnooにいniiさんsan
1.

A male relative by marriage, specifically the brother of one's spouse, who often has a familial bond and connection through the institution of marriage.

2.

A man who has become part of one's family network through the marriage of a sibling or spouse, typically involving a relationship that may differ from that of a biological brother.

3.

A person regarded as a brother due to marriage ties, often carrying responsibilities or expectations of support and camaraderie similar to those found in sibling relationships.

4.

The male sibling of one's partner, who may play a role in family dynamics, celebrations, and gatherings, symbolizing the blending of two families through marriage.

Example:

私たちはまず、あなたの義理のお兄さんに手紙を書いて、もてなしていただいたお礼を言うべきでしょう。