[2] Ajima is credited with introducing calculus into Japanese mathematics.

The significance of this innovation is diminished by a likelihood that he had access to European writings on the subject.

[5][6] Ajima was an astronomer at the Shogun's Observatory (Bakufu Temmongaki).

[7] In 1976, the International Astronomical Union (IAU) honored Ajima by identifying a crater on the Moon with his name.

[8][9] In a statistical overview derived from writings by and about Ajima Naonobu, OCLC/WorldCat encompasses roughly 20+ works in 30+ publications in two languages and 40+ library holdings.