Either it's the same person using an alias/pen-name or one of it is a Circle. Try searching for "おかのはじめ 乱漫" on google. Okano Hajime is written only in hiragana on all his eromanga, I think.
It came from the sky, and invaded our planet to procreate.On an Island countryIt ravaged the area...Women are raped as catalysts, men are killed.Continued on page 6