In episode 5, titled 'House Wars,' the houses compete in a ruthless capture the flag game where each house must steal the flags of the other houses while protecting their own. Each participant carries a card that can be used to duel opponents; the highest card wins, but a 2 can beat an Ace. The loser of a duel is out of the game, and the last house standing wins. Heart House, with players Yumeko, Mary, and Ryan, wins the game, with the bounty being chocolates.

Michael and Yumeko are on opposite sides during the House Wars game, creating a direct rivalry between them in this episode.

Yumeko discovers that Blake's father, Raymond Rowe, is the 'Ray' she has been searching for, identified by a distinct mark on his hand. She plans to kill him to avenge her parents by assembling an explosive device, but her friend Michael deactivates it, believing she is making a mistake. Unexpectedly, the car carrying Blake and his father explodes, killing them both. It is later revealed that Riri, Kira’s half-sister, planted the explosive on orders from her father as part of a mob hit because Ray was an informant.

The key players in Heart House during the House Wars game are Yumeko, Mary, and Ryan. They work together to win the game against other houses.

In the House Wars game, each participant carries a card used to duel opponents from other houses. The highest card wins the duel, but uniquely, a 2 can beat an Ace. The loser of the duel is eliminated from the game. The game continues until only one house remains standing, which wins the competition.