Original:

Masami was living in New York and she thought Americans people are individualistic thant
Japanese people because she has lived different experiences in both countries. She saw different
behavior from each person and their freedom forms to wear. Almost, she was surprised because
she compared old woman's between two countries. She remembered when she was walking on
the street in New York and she saw an old lady was wearing red lipstick. Finally, she understood
that the two countries are different because its has many cultures and different ideas.

Correction:

Masami was living in New York, and she thought American people are more individualistic
 than Japanese people because she has lived different experiences in both countries. She saw
 different behavior from people in each country, for example, in the freedom to choose clothing.
 Also, she was surprised (or: She was most surprised) because she compared old women between two countries. She remembered when she was walking on  the street in New York and she saw an old lady wearing red lipstick. Finally, she understood that the two countries are different because they have many cultures and different ideas.