At every HBS temple, a Buddhist service called Osōko is held several times a month on specific days. O in Osōko is an honorific prefix and Sōko literally means “All HBS followers.” Osōko is also called Goshugyo. Go is an honorific prefix and Shugyo means “practices.” Therefore, Osōko is the Buddhist service that every member is supposed to visit the temple which he or she belongs to and work harder than usual on chanting the Odaimoku, listening to a Gohōmon, and donating Goyushi (the contribution of money to a temple as a religious offering). HBS members discipline themselves and improve their faith by participating Osōko every month.
Generally, the Osōko held on the first of every month is called Gasshi-sōko (Gasshi means “the beginning of the month”), at which members express their appreciation for the days that they were able to have peaceful days last month and pray for their health so that they will able to accomplish their Buddhist practices (especially, missionary works) this month to the Gohonzon.
The Osōko held on the 13th that is the date of Nichiren Shonin’s death is the memorial service for the purpose of repayment for indebtedness to Nichiren Shonin. In a like manner, the Osōko on the 24th is for Nichiryu Shonin and on the 17th is for Nissen Shonin. Although both Osōko and Oeshiki are memorial services for the three great masters, Osōko is a monthly event, while Oeshiki is an annual event. When an Oeshiki is held, priests and followers from other temples are usually invited, but Osōko is held only by priests and followers within a temple without any guests. They are quite different in a scale.
There are also Osōko for the temple’s successive chief priests held on the dates of their death because we were able to encounter with such a wonderful faith in the Odaimoku, the quintessence of the Primordial Buddha’s teachings, thanks to not only the three great masters but also former priests.
HBS temples hold a lot of Osōko every month and encourage their members to participate in the Osōko so that they are able to acquire a habit to visit their temple daily and keep their faith deep.