Timeline

Game order
This differs widely from the publication order, as seen in below examples.

Snow Radish Vacation!! occurs many years before Large PonPon, as seen with Arisu Takatsukasa aging from a young girl to an old woman. Arisu is roughly a similar age to Kagura Inou also working as a waitress.

Even by Summer Radish Vacation, Kagura does not appear to have aged very much, though enough time has passed for her to have three daughters by Tomaru named Rina, Mai and Hajime.

By the time of Summer Radish Vacation 2, Hajime's daughter Rio is probably in her 20s, her daughter Risa is already a teen mom and Risa's daughter Rika is a toddler.

Despite Kagura being Rika's maternal great-great-grandmother, given the short length of each generation it's still not clear whether or not SRV2 takes place before or after Large Ponpon, as Arisu doesn't appear in any of the "Summer" games for comparison.