My Hero Academia Episode 3: Roaring Muscles

All Might explains to Izuku that his Quirk, **One For All**, is a transferable power passed down through generations, stockpiling strength from each user, and declares Izuku worthy to inherit it as his successor.

Izuku, overwhelmed with joy and tears, accepts after initial confusion about how a Quirk can be given. All Might warns that Izuku's current weak body cannot handle the power without exploding or losing limbs, so he assigns a brutal 10-month training regimen: clearing trash from the polluted Takoba Seaside Beach daily, from dawn through school and into night.

During training, Izuku pushes far beyond the schedule, collapsing from exhaustion one day; All Might scolds him for risking injury but recognizes his drive to excel at U.A. High's entrance exam and become a hero who saves others with a smile, then adjusts the plan accordingly. After 10 months, on the exam morning, Izuku completes the task ahead of schedule, having removed every piece of garbage; his body is now toned and muscular, a "worthy vessel" for One For All.

All Might plucks a strand of his hair for Izuku to ingest as DNA to transfer the Quirk immediately, due to the exam's imminent start; Izuku swallows it despite the grossness. As Izuku races to U.A., he encounters his explosive classmate Bakugo, who mocks and threatens him briefly.

Izuku trips while rushing to the entrance gate but is saved from face-planting by a girl named Ochaco Uraraka, who uses her gravity-nullifying Quirk to levitate him upright; she wishes him luck before heading inside, leaving Izuku stunned by the interaction with the cute examinee.