Type B × Type OBlood type compatibility
Type B — The Free Spirit Type O — The Natural Leader
Big energy in both directions. O anchors, B improvises, and the whole thing runs on momentum until someone has to do the paperwork.
For entertainment only. Blood type compatibility (ketsueki-gata aishō) is a popular Japanese cultural belief and is not supported by science. Please don’t use it to make real relationship decisions.
How Type B sees Type O
To a Type B, Type O is easy company — direct, generous, and unbothered by B's tangents. O says what they want, which spares B the guessing that other types demand. B also likes that O will actually come along on the ridiculous plan instead of just endorsing it.
How Type O sees Type B
To a Type O, Type B is fun and slightly ungovernable. O naturally organises, and B naturally declines to be organised, but without malice — so O rarely takes it as a challenge. What O values most is that B is honest. O dislikes being managed politely, and B doesn't do that.
What works
Both are direct, so almost nothing festers. Disagreements happen out loud, immediately, and are over quickly. Socially they're strong — O opens the room, B makes it interesting.
Where it breaks
Two people who both dislike being told what to do. O drifts into deciding for the pair; B, who resents nothing more, simply stops showing up to the plan rather than arguing about it. O reads that as unreliability. B reads O's planning as control. Neither is quite wrong.
By situation
- Dating — Warm, physical, sociable. Runs well while there's a shared project and gets thin when there isn't.
- At work — Strong front-of-house pair. O closes, B invents. Neither should be the one filing the report.
- As friends — The default best-friendship of the chart — loud, generous, and durable across long gaps.
One thing that helps
O: propose, don't assign. B: if you're out, say you're out — silence reads as a yes you never gave.
Every pairing
All ten combinations of A, B, O and AB — each page covers both points of view.
- A × O High
- A × AB High
- B × AB High
- A × B Tricky
- B × O Steady
- O × AB Steady
- A × A Steady
- B × B Steady
- O × O Steady
- AB × AB Steady
Prefer the grid? See the full 4×4 compatibility chart.