Nishimiya is a bit of a tsundere-like boy, wanting to be manly despite his feminine features, blushing at times, and making harsh remarks every now and then. However, it doesn't change his care for his friends. His best friend is Minamoto, and his favorite Sanrio is Little Twin Stars 

His family often refers to him as "cute", which seems to aggrivate him, as he wants to be manly, seeming to have held alot of pent up anger for quite some time due to this. This also caused him to lash out at Kouta and his friends because they were so open about their interests in Sanrio. After he found out that Minamoto liked Sanrio too, he was quick to lash out at him as well and ignored all his attempts to apologize and work the problem out. However, after Kouta had given him quite a lecture when Minamoto collapsed from exhaustion, he started to see the errors of his ways and talked it out with him, apologizing. The two became quite close, but he still had his doubts about Kouta, Yuu, and Yoshino