In the ninth episode of Release the Spyce, Yuki decides to tell the story of her mentor, Nagaho, to Momo.

Mei believes that Yuki should spend some time with her apprentice
Yuki is investigating Moryo, determined to find any vital information on them. Mei decides that it is for the best if she takes over for the time being, which will allow Yuki to go and spend some time with Momo.

Yuki just casually standing in Momo’s wardrobe got a laugh out of me
Yuki goes to Momo’s place, just sort of appearing in her wardrobe. It takes Momo a moment, but she realises that she isn’t alone. Yuki has dropped by to take up Momo on her earlier invitation of going out and doing something fun.

Yuki and Momo go on a date
Momo and Yuki do go and do fun things together, but Yuki also has a specific place in mind she wants to visit. She takes Momo there, and tells Momo a story from two years ago about her mentor. Nagaho Fujibayashi

Nagoho demonstrates her skills
Yuki was scouted into Tsukikage by her mentor, Nagoho Fujibayashi. Of course, Yuki wants a demonstration of her skills before she accepts, and Nagoho completely overwhelms her.
Nagoho reveals the secret to her strength: the love of the city she lives in.

Tsukikage has passed their spirit down through the generations
Moving ahead a bit, Yuki recounts a mission from two years prior. Moryo had hacked into satellites orbiting the Earth, and were preparing to crash them into the major cities of the world. Tsukikage were the only ones that could react in time to avert the catastrophe, so they stormed Moryo’s former hideout.

Nagoho fights Aleksei
Nagoho and Yuki end up fighting Aleksei, who was in charge of Moryo’s operation back then. Nagoho’s senses have been heightened by a drug he injected, but Nagoho takes advantage of that by smashing a bottle of perfume. The smell is overpowering to him, and she knocks him out. However, Moryo had reinforcements.

The Sparrow Woman – AKA Tendo
Nagoho and Yuki fight Tendo and the Puppets she brought along with her. Mentor and apprentice launch a joint attack against their foe, but it doesn’t go particularly well.

The moment where Yuki’s eye got scarred
After injuring Yuki, Tendo makes a run for it. Both Nagoho and Yuki pursue, but Yuki fails to notice that Tendo is leading them into a trap. Nagoho is able to shove her apprentice out of the way. She isn’t so fortunate, getting cut by Tendo. Tendo turns her attention towards Yuki, raises her sword and-

Nagoho is cut down
Nagoho jumps in front of Tendo to protect Yuki, and ends up paying the ultimate price for it. She goes out with a bang, and Yuki has to be dragged out of the place by the other members of Tsukikage.

Momo can feel Nagoho’s spirit from Yuki
Back to the present, and now Momo has a much clearer understanding of why Yuki had a go at her for being so reckless during their previous mission. It also explains why Yuki watches over her the way she does. Momo can feel Nagoho’s spirit from Yuki, and vows to inherit it and carry it on.

Momo helps Yuki with her investigation
After hearing everything from Yuki, Momo is more keen than ever to help Yuki out with her investigation. They end up making a vital discovery, which means that the mission to eradicate Moryo can begin.
Meanwhile, Moryo is preparing to start the mission to eradicate Tsukikage.
There we have it – Yuki did lose her mentor, which was why she got so mad at Momo when they were in Okinawa. I really liked this episode – it has established a link between Yuki and Tendo, which almost certainly means that they will be confronting each other in the future.
I just hope that history doesn’t repeat itself, but the preview for the next episode seems to suggest otherwise…
I also enjoyed seeing Momo and Yuki just hanging out together. Yuki telling Momo that story has given Momo a better understanding of her mentor, and presumably they have grown closer because of that.
With both Tsukikage and Moryo making their moves, I am very keen to see where things will go from here.
Great flashback and the brief glimpses of Momo and Yuki’s date were excellent.
Nagaho was pretty cool. Her death was brutal to say the least. Hopefully Yuki won’t suffer a similar fate as you said.
I’m suspicious of Mei now too.