The rain catches Yuri and Touma in the city and they end up at a flower shop where Touma falls in love with a girl who works there. Kei and Yuri pick up on the computer geek's change in mood, and readily give him love advice on the scary thought of asking the girl out.

A teenage girl named Monica has been training all her life to carry on her family's deadly assassin heritage. Her first assignment is to go after the Dirty Pair. Kei and Yuri go to a vacation resort to relax but soon find themselves on the guard as bombs, traps, and deadly attacks appear wherever they go.