This entry includes the following chapters:

1. Oiwai Sex: Onii-chan no Tanjoubi (おいわいせっくす ～お兄ちゃんの誕生日～) released at Comiket 94, later one included in Otomari Sex Omnibus from Comiket 97.
2. Oiwai Sex 2: Imouto no Tanjoubi (おいわいせっくす２〜妹の誕生日〜) first released online in FANZA and bundled with Oazuke Sex in Comiket 95, later one included ...