One of the oldest tribes of Tamil Nadu, Irulars reside primarily in the district of Tiruvalluvar, Vellore, Villupuram, Kancheepuram, Cuddalore, Tiruvannamalai , Chengalpattu and even from neighboring Andhra Pradesh. Irular tribe people are traditionally forest dwellers and snake catchers. They live in deep spiritual affinity with nature, oral tradition and culture. The Masimagam period is quite profound to the Irulars as it is believed that the spirits of their ancestors come down to bless descendants.
The Irula community assembles on the shores of Mahabalipuram, near the shore Temple, to honor their deity, Kannaiamma, believed to be a tribal warrior who passed away in the area. Participants construct temporary shelters using sarees and tree trunks,creating a communal space for the festivities on the night of the full moon, families engage in various rituals, including
Constructing Sand deities:
Building sand structures with seven steps, symbolizing seven goddesses, and offering flowers, fruits, and lighting lamps as part of the worship.
Traditional Ceremonies:
Performing rituals such as head tonsuing(mottai), marriage solemnizations, and making vows(kuri).
Cultural Performances:
Engaging in music, dances, and storytelling that reflect their ancestral traditions.
The following morning, participants take a dip in the sea, symbolizing purification and renewal.

When the Irulars celebrate the festival, they engage in sacred bathing, in rivers, ponds and the sea. Poompuhar, Cuddalore and Chidambaram are some highlights for sacred bathing. Rivers, ponds and other water bodies are observed to serve as entry points to the spiritual world.
The Irulars engage in several rituals: River worship and purification baths, community cooking and feasting, usually involving millets and wild cuisine.
Historically, the Irular people have faced challenges such as lack of recognition and access to basic rights. The Masi Magam Festival not only facilitates cultural expression but also acts as a platform to address issues like bonded labour, with social workers and authorities using the gathering to identify and assist affected individuals.