^This is fashionable. I dont know what its called, but a split down the middle two pattern button up is a relatively popular type of summer outfit that both guys and girls wear primarily in Japan and some SE Asian countries. I have a few myself, and you pretty much always wear it in summer as you see above, with a white t shirt and jeans with light accesories. It generally is fashioable and looks good, but is hit or miss based on pattern and what you pair with it. Its a very less is more kinda outfit. The button up stands out a lot, so you go very light on everything else to balance it.