Two nitpicks: Japanese sh is not retroflex but either s\ or S, and the syllable /Se/ can be used for loanwords (eg shefu (chef), shea (share), sheri: (sherry), she:ku (shake), she:bingu (shaving)). Whether you want to call it /Se/ or /sje/ is kinda up for debate I guess, but for two things: /je/ doesn't exist as an independent syllable, and for other consonants you can't really get away with doing this so easily – in particular, t and tS are now completely phonemic except for older speakers who still can't pronounce ti, because ti and che are used in nativized loanwords (chekku from check, pa:ti: from party, etc). Similarly, ts can be used before any vowel now, although not as commonly, and again some people don't pronounce it quite "correctly", especially if they're older. Morphologically and orthographically, tSi is represented as ti, though, and when you type on a computer, ti gives ち or チ (/tSi/). Basically these things, even when you have a full set of possible syllables for both 'phonemes', aren't so cut-and-dry.
I meant s\, I just messed up the x-sampa for it.
As for [ti], isn't "team" borrowed as chimu though? I didn't think of "party" as pa:ti: though.
This all reminds me of Israeli Hebrew and how the phonemic status of p/f, t/T, k/x was affected by loanwords.