katiedid has a lovely list of summer fragrances. I want to try them all! But in 下北沢 there is a lovely little store called Art et Parfum that lets you buy small amounts of whatever fragrance they carry. They also make their own blends. I bought 2 types last time. One very sweet Salvatore Ferragamo scent, and one freesia scent apparently produced by an American flower shop. They're both quite nice, but I can't tell how they smell on me. :D Fragrances are a very funny thing. Anyway, it's really fun to try different perfumes.
By the way, perfume is 香水（こうすい kousui）in Japanese.
I also think it's amusing that Ferragamo features three languages on their site. Italian, English, and... Japanese! Who do you think their biggest customers are? Heh.