"Yamachi" - YamatoxTaichi: Popular Boy's Love (Yaoi) relationship in Digimon.
Also, "Yamachi" shows the readers which boy takes on the more 'dominant' role("Seme") and which one takes on the more 'submissive' role ("Uke"), in this case: Yamato - Seme; Taichi - Uke.
If the roles were reversed, the pairing would not be called "Yamachi", rather it would be called Taito.
"Hmm, who'd ever have thought Yamato'd be top..."
The Yaoi pairing of Tai/Taichi and Matt/Yamato in digimon. Very popular among yaoi fans because of the very close friendship between them and them always fighting supposedly to get close to eachother.
One of my favorite pairing in Digimon is Yamachi.