You can get it from http://bbs.mikocon.com under the Vip-section in unreleased.
But you need a vip membership which means you need to donate ones at the site. Doesnt need to be much if you only want this dlc.
Here is a VIP guilde...
Titel: パティシエなにゃんこ Standard Edition
Romaji: Patissier na Nyanko - Standard Edition
Developer: Pajamas Soft
Release: 29.10.2010
HP
VNDB
Getchu
I request the "Standard Edition" of パティシエなにゃんこ with the "super append disc" (スーパーアペンドディスク).
The append disc of this release has extra scenarios.
Here is a link:
http://www.anime-sharing.com/forum/hentai-games-38/japanese-~new~-%5B090718%5D%5B同人ゲーム%5D%5Bshiningstar%5D-break-panic-夏休みだよ-親子丼-%5Brj051340%5D-797728/
Mexa and Rapid are both alive.
Here is a working link for the game:
https://mega.nz/#F!LE4T2ajQ!61AuGBKGRdrAvRTqcWynog
I didn`t found a virus in this one, but check yourself, just in case.
Have fun :)
Here are working links:
http://www.anime-sharing.com/forum/hentai-games-38/japanese-%5B090925%5D%5Bcube%5D-夏ノ雨-28165/http://www.anime-sharing.com/forum/hentai-games-38/japanese-%5B090925%5D%5Bcube%5D-夏ノ雨-28165/