Motohama

Motohama is the other best friend of Issei who made up the "Perverted Trio". Motohama has the ability to calculate a female's body measurements just by looking, which earned him nicknames such as "Perverted Glasses" (エロメガネ Ero-megane) and "Three Sizes Scouter" (スリーサイズスカウター Surī Saizu Sukautā). Like Matsuda, he constantly spreads bad rumors about Issei out of jealousy of his relationship with the Occult Research Club. He does not know that Issei and the Occult Research Club members are Devils. Motohama is known to have better results than both Issei and Matsuda.

(Source: High School DxD Wikia)