It's responsible to make sure everyone arrives back home safely.
Best friends Sora and Kairi have been invited to an out-of-state party.
Sora wants to attend the party with Kairi.
After a long night partying, Sora wants to go home while Kairi does not, but he doesn't allow her to stay there with strangers.
After being at the party for a while, Sora decides it's time to go while Kairi wants to stay, so Sora leaves without her at the end of the night.
Sora and Kairi make it home from the party safe and sound.
Sora never hears back from Kairi the next morning, and her parents report her missing.