The Japanese character which looks like lt sounds like "keh".
To get "geh" it's written lt"
For ANYTHING starting with a "j" sound, needs the character for "shi" (which looks like J backwards) and add the little " after it, making "ji". For anything other than "ji", you add "ya", "yu", or "yo", making "ja", "ju", and "jo". Anything else would be foreign (Jei's name got explained here), which Gen definitely isn't.
Therefore, ge-n-no-su-ke starts with lt"
I'm helpless on the kanji, of course
