Kekkon Yubiwa Monogatari

both are isekai and include a multi-species harem both are ecchi anime that include nudity kekkon yubiwa is more plot-drive isekai meikyuu is more like porn, its MC is more straightforward with his lust 

both series are isekai both MCs are ordinary high school guy both MCs must find brides scattered around their world to expand their harem and develop a relationship with them in order to gain power