I've notice something fun about both of them.

1. They become trainee at the same year
2. Pairing for couple in Shinee's Juliette MV , Dream Team Couple and King of Idol
3. Krystal called him 'Binno' instead of Minho
4. Krystal love to called Soojung over Krystal. Only for people who close to Krystal that called her Soojung just like Minho
5. Krystal is the first girl that called Minho 'Oppa'. Minho admit in on DT
6. Before DT with Krystal, Minho ideal type is Noona. After DT, he change it to someone who has natural straight black hair. [Watch King of Idol. You'll know the answer] Now, he said that he don’t have a specific type. 
7. Minho likes someone who has the same interest like him. [Sports] While Krystal, really proud of being a daughter of boxer and gimnastic. She keep sayin' that she must be good at sports.
8. Minho always steal Krystal away when she's with other guy but not when she's around Jonghyun because Krystal said that Jonghyun is like her blood brother.
9. When f(x) was in promotion of NU ABO, Krystal once wear a bracelet just like Minho wears now but when Shinee was in promotion of Lucifer, Krystal never wear it again instead of Minho who always wear it now. 
10. Krystal loves hat but she not usually wear it. Minho never said that he loves to wear hat but he always wear it.
11. Both of them always works hard to be no.1
12. Krystal said her favourite color is Red but she always wear Blue. [Minho's favourite color]
13. Lately, Krystal not really around Amber instead of Sulli. Jonghyun also not really around Key now but with Minho. [I mean, Jonghyun and Krystal - Minho and Sulli. Both pairing just like siblings]
14. In SMTown Concert, Krystal not playing around with boys except Jonghyun and Minho ever said that if he has GF, he didn't want his GF to be around with his friend.

I'll update more if I found any info again.