The true story of the cap tying Tohru's, Kyou's and Yuki's past has been revealed; in the form of a flashback of Kyou's. In ch119 he was telling Tohru what happened on the day her mother died in that car accident. It was a really.. hmm.. complicated for Kyou, who was right there when the accident that he knew was about to happen happened, to push Kyoko out of the way and risk revealing his true form in public. We all know what his decision was from the outcome, but undoubtably it was one he regretted making for the rest of his life. And for that reason he wouldn't allow himself to get involved with Tohru (yeah, we all know how successful that turned out *rolls eyeballs*). Quite selfish of Kyou, actually. But what can you do? Split second decisions aren't meant to be made by people who're cursed to turn into animals at the contact of the opposite sex, let alone the most cursed of them all; the one possessed by the vengeful cat spirit.
The cap actually belonged to Kyou. It was something Shishou bought for him during the time when they were living together (after Kyou was cast out by his father). It was then blown off by the wind, and of all people Yuki, who just happened to be passing by, picked it up. From that young age, Kyou already harboured hateful feelings for Yuki, so he refused to touch anything that had been "tainted" by the one who was supposedly responsible for his curse. I think Yuki wasn't aware of how Kyou felt at the time or he would've thrown the thing into the dustbin (lol), but the former actually kept the cap in his possession, until that fateful day when he met Tohru crying on the road, lost and alone. At that point in time, Kyou was already in contact with Kyoko, who would come to meet him often at his "sulking spot" and tell him about her life. Therefore Kyou knew about Tohru. One day Kyoko came to him crying and in a panic, saying she's lost Tohru and couldn't find her. Kyou made her a "man's promise" about finding Tohru for her, but before he could find her, Yuki had beat him to it, totally by coincidence. Kyoko told Kyou later how grateful she was to Yuki for leading Tohru back home, and Kyou became angry because he thought he was the one who was going to find Tohru for her, instead of "that rat". Calling Kyoko a traitor for siding with Yuki (hey, he was what? 10?), he never made contact with her again.. until he saw her again on that fateful day.
And that's how the possession of the cap passed on to Tohru. It's sweet really, how their destinies were already tied together at such a young age. And two chapters later, the future is sealed for Tohru and Kyou in the form of a kiss! And Kureno is okay! Thanks to Hatori! Gosh I love all of 'em >_< Yes, even the mentally unstable Akito. Sigh.. no furuba for 3 weeks!