[2] Bharathi (Gautham) is a refined college goer and a gem among his peers, while secretly, he is a daring vigilante who executes corrupt politicians, bureaucrats, terrorists, and anyone who harms the general public.

Bharathi marks his crimes by recording his victim's confessions of wrongdoings in their mobile phones and circulating these as MMSs before executing them.

A wannabe MLA with hidden wealth, a corrupt minister, and a terrorist are executed on camera, and their videos are circulated among the general public.

The common man celebrates the MMS killer, whose actions are an antidote for their resentment towards inefficient and corrupt government functionaries.

Bharathi's mother Manimeghalai (Sriranjani) is a headstrong IAS officer who enforces her duty without bowing to political pressures.

[4] R. Raghuraj wrote the story and screenplay of Appavi and also decided to direct it with the intention of making the youth of the country realize the importance of being patriotic.