Shokei Shoujo no Virgin Road

They give off the same exact vibe at the start of both series and have very similar starting plots. Also Momo looks exactly like Nana funnily enough. 

Great waifus and yuri interactions with the main characters being somewhat part of an organization that eliminates terrorists, but difference is it's setting is more during fantasy medieval era along with magic instead of guns. 

Both anime shares similar concept, assassin girl protecting the (seem to be harmless) other girl. Also, both Momo and Haru shares the same japanese VA, Hisako Kanemoto. 

Big unexpected plot twists, yuri, and a show that leads to think it's your run-of-the-mill story of this genre, only to find, nope! No this is most definitely not with a lot of deeper story.  

Both anime have a similar vibe. The world that they have isekai'd into has a greater mystery to it and larger forces at play. And the antagonists have strong and gripping (and sometimes quirky) character. 

-Both are Yuri fantasy/Isekai animés with cheerful + serious girl duos. 

Both shows have an MC who assassinates their targets in a fantasy world. In the world's greatest assassin, the assassin got Isekai'd into this world to assassinate the hero. In the executioner and her way of life, the executioner executes people who got isekai'd into her world. 

Both series have a character with the same name and hair colors who work as the assistant for their beloved seniors. Also, both series shares the same concept about secret identity. In Release the Spyce, the Tsukikage girls are high school girls, but secretly spies who fight against bad guys. As for Shokei Shoujo no Virgin Road, Menou is a priestess, but secretly an executioner who kills the otherworlders and those who committed taboo acts. 

Both anime we get a girl that love another girl in a very similar manner. both Mc are very happy and energetic girls. 

Both Akari and Rachel shares the same goal, to be killed by their respective partners. 

Both series have a character with the same name and hair colors. Also, much stronger than the main girl of their respective series. While both series have some yuri moments, Machikado Mazoku is a CGDCT slice-of-life anime while Shokei Shoujo no Virgin Road is a dark-fantasy anime. 

this may seem far fetched but when I watch this fantasy style anime, the plot about the two girls travelling together and one of them aims to kill another whilst facing emotional turmoil over committing the act and to go through with it. this notion gave me very similar vibes to 91 days although I must admit this recommendation does not really make me feel the same emotions that 91 days forced out of me. Overall I only recommend this since I get similar vibes, however faint they may be, so it's understandable if this recommendation may not sit well with y'all.  

El Caz and Virgin Road share a similar premise, an odd couple; the paring of a girl on a mission with her target objective, in El Caz's case, Nadie is intending to make Ellis her bounty and in Virgin Road, Menoue intending to kill Akari. Both shows feature magic and fantasy and strange organizations operating behind the scenes. Both shows have yuri themes. One could probably recommend the entire Girls with Guns trilogy, with NOIR and MADLAX being the other two but of the three, El Cazador is the most similar.  

Both feature the death of a main character before it happens as a core focus of the story. Both feature a duo that love eachother and where the one who is left behind must euthanize the one who must die both because to continue living would mean becoming a monster and because facing the death together gives it meaning. 

Both shows have high-quality animation made by some of the best-talented staff. The source materials are incredible too as they take the isekai genre and does a lot of effort with it. They both have: -Incredible worldbuilding with well-thought-out lore and history. -Interesting cast of characters who feel real and can develop through the stories. -A well-built magic system that sticks out from the traditional formula or RPG logic. If you loved Mushoku Tensei and are looking for other high-quality Iseaki or Fantasy works, then The executioner and her way of life is a well-recommended one!