In English, my name is pronounced /ˈiːsə/ (EE-suh); at least, this is how everyone pronounces my name now in the US, so I’ve gotten used to it. However, I should note that Robert Hass seems to pronounce it quite differently on here:
Poetry Everywhere: Robert Hass Translation of Selected Haiku by Kobayashi Issa
In Japanese, my name is pronounced /isːa/ (いっさ); one can also hear it here (about three to four seconds in, although he says it about four times throughout the video):
For those interested in pronouncing my name the Japanese way, Gemination:Japanese and Sokuon may also be useful.
The name is taken from Kobayashi Issa (and, incidentally, has just about nothing to do with the Arabic name for Jesus in Islam).