I don’t know for you, but it happen to me once in a while that when I watch a certain anime character, I can’t help but think that some character look alike. If can be physically or the way they act.
The very first time I saw Izuki Shun (Kuroko no Basuke) on-screen I just kept thinking he was looking like Roy Mustang (Fullmetal Alchemist). They don’t know it but they are brother from a different parallel universe
The same goes for Nanase Haruka (Free!) and Fujiwara Takeru (Prince of Stride)
Dark hair, blue eyes and both are obsess by their sport…Haru stop swimming and start running.
The resemblance between anime character doesn’t stop to those above. After watching Kuroko no Basuke, I realize that Kise Ryouta reminded me a lot of Yuki Eiri from Gravitation. Then I watch Haikyuu!! and I notice that Kise and Oikawa have a similar childish attitude that annoyed the captain are the ace. Funny fact, 5yrs ace Kise annoyed the Kaijou captain and 5yrs Oikawa captain annoyed Seijou ace.
And after reading the latest Seraph of the End volume that I bought I notice, Tsukishima had enough of hitting a volleyball ball and decide to kill vampire OR Kimizuki had enough of fighting vampire and decide to play volley ball, you choose.
I know there is a lot more I could write about, but I stop here.
If there is any other one you have in mind let me know in the comment below.