Aguero has angular, cobalt blue eyes; ultramarine in the first part, and a deeper cobalt in the second part. He has silvery, blue hair (as is the norm for those from the Koon Family) that reaches his shoulders. His bangs cut across his forehead and hang just over his eyebrows. On occasion, he sometimes puts his hair up in a small ponytail. He's got a small build but somehow still muscular. Several characters remark him as good-looking or handsome (even SIU says so in FAQ).