Title: Shounen to Chijo Oneesan-tachi no Shiawase H na Apaato Kurashi
Original title: 少年と痴女おねえさん達の幸せHなアパート暮らし
Length: Short (2 - 10 hours)
Year: Japan 2014-07-27, English Patch 2015-09-06
Developer: aomizuan
Publishers: aomizuan
Language: English
Voice: Japanese
Translation: m1zuki

Description:
Sekitani Jun is a timid and docile sixteen year old schoolboy who intends to eventually follow in his grandfather's footsteps and become a Buddhist priest. After his parents have to temporarily relocate, Jun's friend's mother Miyuki agrees to accommodate the boy in the apartment complex, where she is a landlady. To Jun's great misfortune, all the other apartments in the building are populated by perverted nymphomaniac sluts, who immediately set their sights on him.

Important:
1. You need to change locale to Japanese.
http://erogedownload.com/faq/changing-to-japanese-locale-on-windows-7/

2. No need to install.

Screenshots: