A Japanese holiday cebrating the life and works of Tezuka Osamu. It is typically celebrated about twice a year, both on important days in Tezuka's lifetime: his birthday of November 2nd, and the day of his passing, February 9th.
There is a separate "Comics day" with the same name (observed on July 17th), however it is in celebration of the publication of the first issue of British satire magazine Punch.