The upcoming If My Heart Had Wings (Kono Oozora ni, Tsubasa wo Hirogete) is censored and therefore completly all-age It looks kinda tear-jerking but I haven't read it so I don't know.
Kira Kira has an all age release. Its mostly comedic but I have heard that some parts of it are very sad.
There's also Higurashi which certainly has many tear-jerking parts though they're never the main draw.
True Remembrance and D.C. I.F. might also fit but that's certainly pushing it. (The latter especially, I wouldn't ever cry to a Da Capo game, but there are people that do so).