This is my friend and student and she was telling me about the trials of getting herself ready for her daughter's kindergarten graduation. Most mothers wear black or at least somber colors. A few mothers will go all out to wear a kimono but it involves a lot of work. Mrs. Matsumoto's kimono is her mother's but she said she had to have the sleeves shortened in order for it to be an appropriate kimono to wear to a formal event (for her age). That alone cost quite a lot and then she was told she needed to buy a suitable obi (belt) and under-kimono. And I'm not talking about hundreds of dollars. Add a zero. In the end she resewed one of her mother's under-kimonos and found a lovely obi at a recycle shop. (We went looking together and there were SOOO many beautiful kimonos for a piddling!) She had her friend dress her but often it is necessary to go to a professional kimono dresser to even get into and tie the obi in the fitting knot in the back.
At the elementary school graduation, all the 6th graders wear their up-coming jr. high school uniform as a sign of formality (and the mother's are in black again). I talked with one of my English students on his way back from graduation on Thursday and he was wearing the black high collar traditional uniform seen throughout Japan. When I first came to Japan so many students were wearing this traditional black outfit that I thought there was a national funeral going on! (picture from the internet)
And on the way back from kindergarten graduation I stopped in to a bakery and found these little filled breads on sale. They say things like "Congratulations" and "Happy Graduation". I think they are filled with chocolate cream.