Spunky, I feel you've missed a key element here. Let me demonstrate to everyone the true
meaning of Emi's shirt.
X = Chi (greek letter)
Chi is the first letter of the Greek "Χριστός", meaning "Christ"
Hence, usually, Xmas = Christmas
As above, "Mas" = "More" in Spanish
THUS EMI'S SHIRT READS
"Let's More Christ"
This makes no grammatical sense. It may become clear if we take the first letters of each of those three words - LMC - and assign a numerical value to each letter corresponding to each letter's place in the alphabet. This produces 12, 13, 3.
12 - 3 = 9
The 9th letter of the alphabet is "I". Further:
13 + 9 = 22
The 22nd letter of the alphabet is "V".
This means Emi's shirt actually reads:
As everyone knows, IV is "4" in roman numerals. Further, the aforementioned letters, "LMC", may be rearranged to "MCL", which is equivalent to 1050.
1050 - 4 = 1046
On December the 20th of the year 1046 AD, Pope Gregory VI abdicated.
VI is "IV" backwards. Also, the event occured in December. What else occurs in December? Christmas. How else is Christmas spelled? "Xmas". THE VERY SAME XMAS EMI WANTED TO "LET'S".
Therefore, Emi's shirt actually means that TheHiveMind - the man who wrote Emi's route - is actually the reincarnation of Gregory VI, and Katawa Shoujo
(at least Emi's route) is a complex allegory for man's relationship with Christ and the holy trinity.
The truth is out there, people. You just have to look for it.