にいnii
1.

A male sibling who is older than oneself, often considered the protector and guide within the family structure.

2.

A respectful term used to address or refer to male friends or seniors, conveying admiration or deference in formal contexts.

3.

A term that may include not only biological older brothers but also can refer to older male relatives or family connections like a brother-in-law.

4.

In literature or poetry, it can signify an older male figure or mentor in a more general sense, extending beyond familial relationships.

5.

A casual term of endearment or camaraderie used among men to express closeness or familiarity, signifying a bond similar to brotherhood.

あにani
1.

A male sibling who is older than oneself, often carrying the connotation of a protector or mentor within the family hierarchy.

2.

A term of respect used by males to address older male friends or acquaintances, particularly in formal contexts or written communications.

3.

A designation for a male relative who is the elder son in the family, potentially including step-brothers or brothers-in-law.

Example:

私のは技師になった。

oにいniiちゃんchan
1.

A term of endearment used by younger siblings to refer to their older brother, often conveying affection and a close familial bond.

2.

A casual and affectionate way for someone to address or refer to an older male figure, highlighting a sense of familiarity and warmth in their relationship.

3.

An informal expression that not only signifies an older brother but may also imply a protective or caring role within the family dynamic.

Example:

「百八といえば煩悩の数だ」「お兄ちゃんはどんな煩悩があるの?」「言ってもいいが、検閲削除になるぞ」

あにき兄貴anikiアニキaniki
1.

A familiar and respectful term used to refer to an older brother, conveying both affection and deference.

2.

A title for an older male figure, especially among young men or members of organized groups, indicating a position of seniority or influence.

3.

A term expressing acknowledgment of someone being older, often used to show respect or reverence towards a male who has more experience or status.

Example:

「そっか。暇なら掃除しといて」「なんだそれ。兄貴をアゴで使うなよ」

きょうだい兄弟kyoudaiけいてい兄弟keitei
1.

A relationship between individuals who share at least one biological or legal parent, encompassing all types of siblings including brothers, sisters, half-siblings, and stepsiblings.

2.

A term expressing a bond or connection among males who feel a sense of camaraderie or closeness, often used in informal settings.

3.

A designation for individuals who are connected through shared upbringing, whether by blood or law, which may include both traditional and non-traditional family structures.

4.

A more formal or archaic term used to refer to brothers and sisters, reflecting a historical or cultural context.

5.

A label applied to individuals who have formed a brotherly bond through mutual agreements or commitments, similar to that of biological siblings.

Example:

ライト兄弟はエンジンで動く飛行機を飛ばすことに成功した。