Matsubue Takaomi, together with his girlfriend, Arika Togawa, kidnap Mikoto Urabe in the Anime OAV during the Summer Festival. Matsubue is the main character of another of Richii Ueshiba's stories, but like the main character of Mysterious Girlfriend X, namely Mikoto Urabe, he also is quite a mysterious character himself. And both main characters have an intimate friend that they are attached to, who stands in awe of them. By some unknown process, Matsubue comes to have knowledge of the unique relationship that Mikoto and Akira enjoy because of the Drool Bond that they have between themselves. Matsubue is probably not Drool Bonded to his girlfriend, Togawa, hence he may be curious about this very mysterious, but intensely erotic relationship that keeps the two lovers together.
Matsubue concocts a test to reveal the strength of such a bond. With the help of his girlfriend, working together as a team, and both wearing fox spirit masks, they kidnap Mikoto, and place her in a very dangerous, life threatening situation. Matsubue and Togawa then observe how Akria and Mikoto work together to aid in the rescue of Mikoto. Although the test was a risky venture, it appears that Matsubue does not have any real ill will towards Mikoto or Akria. He just wanted to examine the two to learn more about their relationship. At first glance, it seems that he was successful in his quest. However, he actually was the loser. Why ? Because, the deep, personal, intimate and erotic love that already exists between Mikoto and Akria, he now knows can only ever be an unachievable dream for him and Togawa. Afterwards, when the test is over and the 'guinea pigs' are gone, Matsubue and Togawa muse about their own nebulous and mysterious relationship, perhaps feeling irony for not being able to ever have that kind of love that they both witnessed Mikoto and Akria now enjoying, and the erotic love they can revel in forever.