From Babriel Glessing as well, 'Destiny', with its Ranma/Haruka Tenou: http://www.fanfiction.net/s/3590026/1/Destiny
On a similar spectrum, 'SeaHorse' by Vahn, featuring a rare Ranma/Michiru Kaiou: http://www.fanfiction.net/s/5876464/1/SeaHorse
Both are very adorable fics.
...Damn, now I want to see more fics with similar premise...