LoL! That Chelsea bento thing made me laugh. XD
Yes, it is indeed written as チェルシー (cherushii).
However, do you know how to say this?
I suggest reading
here, but remember that when a native talks quickly it may sound like 'Che-shii' or 'Chel-shii'. Also, you should do a little research on how shii is pronounced, too.
On the topic of that, actually, check out fu, fe, fi and fo as well, because it's not that similar.
PM me and I can explain.
Best of luck,
Megan ^^