Yamato Ishida, at 11, has seen many hard things. His parents, Masaharu and Natsuko, got divorced when he was 7; he went to live with his dad, while his 3-year-younger brother Takeru went to live with mom. Ishida-san is a quite good person and he sincerely tries to be a good father to Yamato; however, he works as a full-time reporter in a TV station, and his tight agenda leaves very few time for him and Yama-kun. Yamato, at some point, practically raises himself, seeing that he can't count on his workholic dad for everything, to grow up in a cool youth who apparently doesn't care for anybody than himself or his brother, whom he can barely see at school or at weekends. 

At the Digiworld, Yamato starts as a troublemaker. There's rarely a time when he doesn't goes into fights with Taichi Yagami, a boy his age who acts like the un-official leader of the team. This bond of love-hate makes itself strong to an obsessive point from his part, as he's somewhat afraid that Taichi's self-assurement is a 'flipside' of all his doubts and insecurities. Later in the Dark Masters saga, there's a point when the two boys have a 'GREAT' fight, and Yamato ends up leaving the group with his partner Gabumon to sort his feelings and the meaning of his Tag and Crest, the ones of Friendship; he doesn't come back until the last fight against Piedmon. At this rate, all his darkness has left him, so that he has no doubts anymore abou his role in the Battle of the Worlds... 

In Digimon 02, 14-year-old Yamato lets (like Jyou) his hair grow longer. Now he's the lead singer and bassist of a popular highschool band with lots of fans (Daisuke's sneaky and VERY genki older sister Jun in between), and there are STRONG hints that his relationship with Taichi may be going far beyond their simple friendship... 

Part 1: Yamato and Jyou? 

I can see this one happening, guys. One, Jyou has a good relationship with Takeru (he has saved the little guy TWICE, both at the risk of his own life, giving him brownie points). Two, Jyou envies Yamato's calm-cool-collected attitude and wishes he could have it. Three, Yamato appreciates Jyou's selflessness and learns to respect it. Jyou made Yamato's crest glow in 'Weregarurumon's Dinner', by rescuing Takeru and nearly getting himself killed. The way Yamato yells his older friend's name, sorry for being mean to him minutes before, is heartbreaking; and after it, Garurumon is able to digievolve to its champion form, Weregarurumon. If Yamato finds himself alone (read: without Taichi *lol*), he may turn first to the 'old reliable' for comfort, who has known of his loneliness and understood him to a surprising point. 
 
 

This is the controversy point in the Yamato-agenda. It has been center of many fights, flame wars, and etc. I personally don't like it, and not only because I'm much more fond of Jyou/Mimi, but because it has no real evidence whatsoever. The few times Matt talks to Mimi, is to make her shut up or something. The only exception is the Puppetmon chapter, when he defends Mimi from Taichi when the Yagami kid insensitively yells at her for mourning over their dead Digifriends. So much potential they had - it pissed me to find it gone, after the first chapters in the File island. 

And there's another reason for me to hate MiMato: the rudeness of the 80% of its fandom, who have built themselves an horrible fame by stealing Japanese fanarts, inventing false information, flaming others who don't share their ideas. Mina-sempai knows of it, she discovered stolen Mimato fanarts herself... So, their attitude doesn't help a little to make others like the pairing; they rather give the Matt/Mimi pairing a bad name. I'm sorry, but thanks to it, I can't like this couple, no matter how hard I try. 
 
 

A favourite in Japanese Yaoi pages ^^ I personally find this coupling kinda cute. Both boys have serious family problems, and lack of true security. They also went off in the forests in the Piximon chapter to... eeeh! ^_______^ erm, to find their crests of Knowledge and Friendship. Something else was left to our sick imagination. But somehow, I think that both TaiTo and TaiShiro are more appealing. They both interact more with Taichi than in between themselves.