An ordinary college student SEBASTIAN gets kidnapped by Goblins on his way home from a party. With the desire of getting some goblin wine, he makes a deal with the Goblins. Sebastian brings home a young Goblin, RRRUBY, who does not understand anything about human society. Sebastian must teach it the way of acting like a human being. At first, Sebastian does not want to take care of RRRuby; instead, he only wants to enjoy his prize. However, he then learns that without taking responsibility, not only will he not be able to get his prize, but also RRRuby might get seriously injured because of his negligence. They have a short but rich time.