Biju is one of the major festivals of the Chakma tribal community. This festival is celebrated on the last two days of the Bengali year and on New Year's Day.
In Khagrachhari, the Chakma community began their merriment by setting flowers adrift on the Chengi river and other water bodies in the area. The children bathed in the river and visited the elderly for blessings.

Fulbiju is more than just a festival. It is a deep reverence for the cultural heritage of the tribal community, a testament to the importance of preserving traditions and passing them on to future generations. It is a celebration of life, of hope, of the promise of new beginnings. As the tribal people bid farewell to the old and welcome the new with open hearts, they are filled with a sense of possibility, knowing that the year ahead will be one of beauty, abundance, and grace.

Fhul Biju is celebrated on April 12. On this day, before dawn, children go out to collect flowers. One part of the collected flowers is worshiped to the Buddha and the other part is floated in water. Houses are decorated with the rest of the flowers. Mul biju is celebrated on the last day of Chaitra month i.e. 13th April. On this day, the Buddha statue is bathed and worshiped in the morning. Children bathe and bless their elderly grandparents and great-grandparents. Many types of delicacies are cooked on this day including birani semai pajan (a type of curry made from a mixture of different vegetables) at home. Friends and relatives visit from house to house and are entertained with these dishes. Wandering all day and night. The first day of the Bengali New Year i.e. 14th April is observed as Gajya Pajya Din (Falling Day). Even on this day Biju is in a mood.