Miyako herself is a 12-year-old schooler, the youngest of the four children (3 daughters and a son) of a nice and normal married couple who run the family's convenience store. When the Digiworld affair 1 happened, 9-year-old Miyako supported ardiently the cause of the Digidestined, and she sent mails of support and courage to Koushiro while he and the other kids were hanging around the Digiworld for the second time. Gennai-sama took this in consideration, so that when the Digiworld was in trouble again and six of the Digidestined weren't able to help directly (they've passed the way from childhood to adolescence), the old man chose Miyako along with two other kids (Iori Hida and Daisuke Motomiya) to join the remaining kids, Takeru Takaishi (Miyako and Iori's neighbor) and Hikari Yagami (Daisuke's crush) and defeat the new troublemaker, a heartless boy genius known as the Digimon Kaizer (who results to be Ken Ichijouji, a top ten student and Miyako's first crush). 

I'm not going to deeply spoil you with what happens in Digimon 02 itself. It hasn't been released in South America still, and I've gotten this info online mostly, so I'm afraid that I'd most likely commit lots of errors. So now, I'll tell VERY briefly what I see of Miyako when she interacts with Mimi, Koushiro or Jyou... 
 

 

FIRST POSSIBILITY: MIYAKO AND JYOU? 

The less possible, the sooner in sight. They have in common little more than the glasses use and the long hair (though Jyou's still much shorter...). Jyou and Mimi are the old Digidestined who less come to help, though they're always in contact with their friends: 13-year-old Mimi is in America, while 15-year-old Jyou is studying hard for the highschool entrance exams (in the first episode he appears, Jyou is getting ready for a test with some schoolmates). I haven't known of, nor witnessed many evidence of a deeper interaction between those so-called 'nerds' of the series, as the newbie Jyou-san mostly interacts with is Iori, who sees him as the older brother that he never could have. Though they look cool together, I've gotta say... :P 
 
 

SECOND POSSIBILITY: MIYAKO AND KOUSHIRO? 

Hum, this is more viable, I think. Miyako and Koushiro went in the same PC club before Digimon 02 starts ('You... you're the great Izumi from PC clubs!!', she says upon recognizing Izzy as a Digidestined), and in the first half of Digi 02, they use to interact quite a lot. Miyako admires Izzy's skills with PC's, while Izzy feels that he can rely on her being the oldest of the new Digidestined and somebody who shares his same intrests. This is one relationship that HAS actually some possibilities, as a 'side-b' of Jyou and Mimi, so that Kou-chan's not alone if he loses the love fight for one of them... whoever he/she is.  ^______^ 
 
 

THIRD POSSIBILITY: MIYAKO AND MIMI? 

I'm saving the (IMHO) best for last! But again, I'll put here a warning.  The following has YURI contents, meaning, 'a girl in love with another girl'; it involves a question that many Digimon fans have been discussing: IS MIYAKO A LESBIAN? If you don't feel like you can put up with my opinion on this, you better leave this part of the corner. It's for your own good, so you better do. 

From Digi 02's chapter nº 6, which is the first one where Mimi appears, we've seen the inclination that Miyako seems to feel for the (now) pink-haired, slightly older girl. Many Digimon fans believe that Miyako's exaggerated admiration of Tachikawa is a symphtom of her future (or not-so-future) lesbianism; kinda in the way that Kimagure Orange Road fans (still) discuss about Kyosuke's cousin Akane's 'crush' on Madoka Ayukawa. 

The picture above is a part of a longer (and rather hilarious) scene where Miyako has a daydream with her and Mimi in a sorta perfect place, with perfect clothes, and even perfect makeups, etc.. I've also seen some screencaps of Miyako nuzzling her face against Mimi's chest and breasts, a 'mirror' of 01 Takeru's 'crotch-nuzzling' sequences with Taichi and Yamato. And it seems that she keeps on going strong for the whole 02 series... 

My opinion? Weeeell... * scratching head* Being a straight girl myself, I don't look at other women *that* way, and I won't go further about it. But I also have no major problem about the girls who do. I'm rather acceptant of lesbianism as I'm of homosexuality; so, at the question, I just say 'Maybe' and accept the possibility. So, if Miyako is really a lesbian, or her adoration of Mimi finds its base in the typic 'teenage-admiration' stage ('you know, you wanna find a role model to follow...'), I can care less, if not for using it in a possible fanfic (My first Yuri? Who knows...). 

Am I not ambiguous, ne? *lol*