Vento Aureo - Chapter 10 
Polpo lights a lighter using the fingers he previously seemed to chew off. He then asks Giorno what the most important value in selecting someone is. Giorno replies, saying that the most important value is what talent, and reveals the stolen wallet of one of the security guards. Polpo corrects him, saying that the most important value is trust. He explains his test to prove Giorno's reliability: to keep the lighter's fire lit for twenty-four hours.
To join the gang, Giorno accepts this test. His first obstacle is to get through a body check without the guards noticing the lighter. He passes the initial body inspection by hiding the lighter in the corner of his hand. However, one of the guards asks Giorno to open his hands if he wants to leave. Cornered, he turns the lighter into a flower, with the lit flame hidden between the petals. Believing it's harmless, the guard is tricked into letting him free. Giorno leaves the prison, the first obstacle avoided.