The Otaku culture, like other hobbies, sets aside a number of days each

year to commemorate events, ​people, or media creations. These annual

celebration days typically are marked by a general meet up after work

and sometimes by activity, and by public and private ceremonies. Many

of these are optional and have been made for bringing people together

who share the same interest and not everyone in the interest

participates. To be an Otaku people who are not in the culture and are

casually interested as individuals and/or private businesses are not

required to observe these.

Annual Celebrated Days in the Otaku Culture are optional and depend from

person to person and are mostly run by groups who are excited about the

days meaning of celebration itself. Annual celebration days are often defined

to occur on a particular day of certain months that don't overlap with other

dates in the same month. With a few additions there hasn't been too much

movement of celebrated days, but renaming as time transforms the meaning

the days originally had. While most of the days are in celebration of real

people making fictional things there is sometimes food and festivities on the

days with sales of goods and services that are associated with the days

themselves.​