The Law of Ueki, Vol. 5: Dogra Mansion Showdown
Seiichiro Sano has joined the Robert's 10! Inumaru comes to  Ueki asking for help in getting Sano out of the group. At that point, Ueki  and the others receive an invitation from Robert to "Dogra Mansion," the  amusement park in the Underworld, where Sano and the new members of the  Robert's 10 await to battle them. Upon arrival, Ai finds herself selected  as the first player. Her opponent, Kabara, is a professional hunter! Ai  goes into her very first battle with no superpowers to rely on!!