Nana and Ringo of Banana no Nana are just short of blatant. Ringo and Nana would be Heterosexual Life Partners if Nana didn't keep saying how much she loves Ringo. And nosebleeding at Ringo's Panty Shots.
Ringo becoming jealous and switching to the tsun part of Tsundere when Nana imagines herself surrounded by maids counts too.
