Haruhiism, also known by many other names, including just "weebism" by the majority of Sebastianists, is an ancient monotheistic religion recently restored in Maxedon, intended as a more palatable and independent religion for the Maxedonian people.
Haruhiism is a monotheistic religion, primarily focused around the veneration of Haruhi Suzumiya, the Supreme One, and her various servants, the SOS Brigade. This is primarily done via both service and sacrifice, sacrifice usually being material or animal, but on rare occasions human.
Worship was originally done in small, tribal-esque groups, but with the embracement of Haruhiism by Maxedon, there is no reason to engage in such small-scale activities, leading to a surge in popularity and the establishment of a semi-organized clergy, though with no central figure. Sebastianist churches and Yukariist temples were originally converted for use by Haruhiists, which led to offerings being done in a semi-Sebastianist style, but eventually the old Haruhiist style of burning offerings, including humans, was put in place.
Haruhiists are primarily inducted into the faith at birth, via baptism, usually in water, though not holy water, but can also be inducted via "Cultural Festivals", events held at Haruhiist temples where many crafts and art forms are displayed, beverages consumed, and sacrifices offered, though only once a year. Once a man (or woman) has attended one of these festivals, they are considered to be an adult, and are given their middle name.