The only issue I have is with the first one and that tree in the background distracting from the child. The others are photojournalism quality, almost National Geographic. They really capture the essence and fun of being a child. Wonderful. Wonderful children as well.
#6 is almost like an old Kodachrome image, the colors are saturated in a similar way. Are you shooting on your camera with it set to saturate colors more so than usual? Part of it might be the exposures are a tad on the bright side. Keep in mind that some of the Japanese cameras have meters that over expose slightly because the Japanese are fond of brighter colors. I would try sometimes to underexpose 1/3 stop or even 1/2 stop and see how it looks. But because of the subject matter, being children with the bright clothing and fun feeling to the images, the brighter tones work well in this case.