According to Raww Le Klueze, global admin of the Suikosource forums, there is a hidden marriage proposal spoken by The Castle Keeper zombie in Neclord's castle that can be found in the game's files in ve3.bin and ve6.bin. There is no known way to access it in-game. Translated to English, it reads:


It's unknown who Kazuko is or who wrote this proposal. This text is only believed to be present in the Japanese version of the game, with the North American version replacing it with a repeat of some past dialogue with the zombie before ending with the "Mwah!" replaced with a single "Yuk.".