Looking to read a romance manga that has the main guys love interest to be more of a kuudere/tsundere type. I would like it to be Seinen/Shounen. I can't really get past the Shojou stuff so please recommend me anything but those. Thanks!

Do you want the main character to be a girl or guy?
If guy then maybe Psyren its shounen, it is more of an action manga though but the FL is kind of tsundere if I remember correctly
Zero no Tsukaima girl is very Tsundere
Toradora! Again FL is very Tsundere
ReLIFE Sakurasou no Pet na Kanojo haven't seen either of the two but I have heard that the female lead's are both kind of the kuudere type.

In all those the MC is a guy and they are all either Seinen or Shounen. Hope that helps.

Shoo, Nothing to see here!