A Simple Thinking About Blood Type

A Simple Thinking About Blood Type is a South Korean four-panel webtoon by art teacher Park Dong-sun under the art name "Real Crazy Man". The webtoon is themed around Japanese [theory of blood type personality|blood type personality classification] and is serialized on Dong-sun's blog. The webtoon has been published in book form and has been adapted into an anime series.

Releases and adaptions

A Simple Thinking About Blood Type was first serialized on Dong-sun's blog as a webtoon. Japanese publisher Times Culture later published the comic in book form as Ketsuekigata-kun! in 2013.
A short anime adaptation was made by Japanese production houses Assez Finaund Fabric and Feel in 2013, with a second season in January 2015. Zexcs co-produced a third season, which began airing in October 2015. A fourth season aired in 2016.

Characters

Each of the voice actors also represents their own blood type.
;Type A-kun
;Type B-kun
;Type AB-kun
;Type O-kun
;Type A-chan
;Type B-chan
;Type AB-chan
;Type O-chan