The fourth episode of Release the Spyce is one that focuses on Mei and Fu.

Mei’s pick is chipped, but it is the only one she can get into the groove with
The episode starts with a flashback to the time that Fu first met Mei. Fu was aware of Mei busking before, though this time around Mei calls her out. Fu’s family don’t have the best financial situation, and that led to Fu feeling down about moving on to high school – she had the grades, just not the money. Mei can see she is feeling down, and sings a song for her.

Fu lives with Mei, and is the more responsible one of the pair
In the present, Fu is living together with Mei and she happens to be the more responsible one of the pair. Mei just wants to spend her money on snacks and her guitar. When Fu moved in, they both agreed to keep a household accounts book – Fu is more serious about it. However, the pair act like they are a married couple.

Fu goes undercover on her own
Moving on, Fu witnesses a drug deal and decides to go undercover on her own to track the culprit. However, she was strictly told that apprentices were not to act on their own. She ignores this.
Fu is able to track her target for a short while, but loses sight of him when Yuki, Hatsume and Mei discover her. She is admonished for actions afterwards.

Mei and Fu tell Momo shut up in sync
Mei and Fu clash heads once again, with Fu telling Mei to act more like a mentor should. As the two argue, Momo tries to step in but she just gets yelled at. This fight goes on for a little while, though the two are forced to put their differences aside when they have a mission.

Mei saves Fu
During the mission, Fu insists on going ahead despite being told to prioritise her own safety. She comes face to face with a group of enemies, and Mei ends up getting injured whilst saving her.

Mei insists that it was her own fault that she got injured
Mei and Fu were able to complete the mission, but Yuki tells them that she may have to rethink their mentor-student relationship. Mei insists that it wasn’t Fu’s fault, and Fu happens to overhear from outside the room.

Fu moves back in her with family
Fu decides that it is best for her to move back in with her family. She leaves a note for Mei, but ends up having to face her when she returns to pick up some forgotten textbooks. Fu tells Mei that she feels like she treats her like she is useless, though Mei isn’t quite able to realise just why Fu has chosen to leave.
Back at her family’s home, Fu tells her sister about her ‘roommate’. Fu’s sister can see that Fu really likes her ‘roommate’, even despite her bad points.

Fu offers a gift to Mei

Mei teaches Fu guitar
Following that, it seems that Mei and Fu are not straying from each other’s thoughts. There is also a flashback that shows that the pick Mei uses was originally a gift from Fu – it’s a precious item.

Fu gives Mei a new pick
Back to the present once more, and Fu meets up with Mei. She gives her a new pick and apologises for what happened. She just wanted her mentor’s approval – with this, Mei comes to understand Fu’s feelings better.
The two reconcile, and the target Fu was tracking earlier just happens to pass by. Mei and Fu immediately pursue him.

Mei fights the target whilst Fu provides support
Together, Mei and Fu are able to bring down their target and gather more intel on their foes. Said intel only provides more suspects, but it seems somewhat likely they are linked to Moryo in some way.
The episode ends with Mei and Fu completely reconciled, and some excellent ending credits showing the two together.
This episode of Release the Spyce was excellent. The relationship between Mei and Fu was great, and we got a nice little action scene at the end where they were able to properly demonstrate their trust in each other.
The pair did have to butt heads, but ultimately their bond only grew stronger. Even though Mei is the mentor in the relationship, she is still learning. In this case, it is learning why Fu works so hard for her.
Presumably we will also see episodes that focus on the relationships between the other pairs in the future – I very much look forward to seeing them if they are as strong as this one.
Decent episode. The villain they fought was creepy in a comical sort of way. Yuri fans are sure to like the clips that played out during the ending.
Pretty sure the other couple building episodes will be as excellent as this one. Momo X Yuki’s will most likely be the bestest since they’re the leads and all.