Dinner

I came home late today.

A collleague of in our department resigned. We came had dinner at a restaurant maned named 红辣椒 - Red Chili Pepper to have dinner.There were about 1A total of about 12 persons and four 42 were Japanese. Most of our colleagues can speak Japanese,So,They talked chatted3 happily. but I was very bored. However I kept a smiling face, although not knowing nothing about what they said  were saying.Oh my God4. !It taked Took several hours for their conversation to end. So tired....

1.  Since you are writing informally, then you do not need such formal structures.
2.  If you Roman numerals to represent the numbers, you should be consistent.  If you spelt them, then you should not use Roman numerals later.
3.  A chat is an informal talk.
4.  Some religious people take offence in using the "God" even in such expressions.  To avoid such awkwardness, one can always use the word, "gosh" as substitute.

dinner

I came home late today.
A colleague of our department resigned. We went to a restaurant named 红辣椒 (Red Chili Pepper) to have dinner.There were about 12 people,and four were Japanese.  Most of our colleagues can speak Japanese, so they talked happily.  I was very bored.  I kept smiling,knowing nothing about what they said.Oh my God.It taked several hours to end.So tired.

哈哈，我懂你！When I was in China, I was always doing the same thing.  I always wondered, what if they are talking about me?