Magia Record Story Whereabouts of the Feather
The following is a summary posted on 4chan's /pmmm/ general by Summary Anon.
Shizuku helps Magius by opening gates to connect different parts of Japan in order to lure witches to Kamihama and she earns money from this. She joins Magius after being brainwashed by Mifuyu since she is still cold with Ayaka when she and Mitama made fun of the destinations she travels to.
There she meets Ryou and Ikumi who tutored her about Magius but also secretly aim to help Shizuku escape since they are against Magius's methods in brainwashing people to join.
In the process, the three became very close, enough that they purposely lost to Shizuku when she escapes. Even the items she used to escape with were given by the two.
Shizuku decides that her place in life is next to Ayaka where she can drop her guard and let Ayaka's energy fling her around. While she regrets that Ryou and Ikumi will become her enemies, she still hopes they can gather again to have food like usual. The feeling is mutual.