You can't really.
http://en.wikipedia.org/wiki/Katakana
The closest you can get is:
ヴァ va ヴィ vi ヴ vu ヴェ ve ヴォ voヴャ vya ヴュ vyu ヴョ vyo
Chat with our AI personalities
さ
Love in Japanese is 愛 Phonetically it is Ai
Learn
セバスティアン
According to wikipedia, this is Kuromi's Japanese spelling: クロミ