Shy, Vol. 2 by Miki Bukimi

Shy?_Ts shown she can handle the basics of being a hero, but with the boy known as Stigma still at large, that might not be enough. Determined to become stronger, she holds a mock battle against the British hero, Stardust?_"one of the most famous figures in the hero world, and a merciless opponent. With her status as a hero on the line, can Shy awaken to new powers!?
Binding: Paperback / softback