The film's story will deal with Misono Alicein's past.
https://dreamanime.fun/anime/watch/197606-servamp-movie-alice-in-the-garden-english-sub This is the only available link that the subtitles don't cover the whole screen but you have to tolerate the MOVID banner. I spent hours looking for another link or to even buy the dvd but there is no other option. Save yourself the wasted time and just trust me. I loved this movie, I was hesitant to watch it because I wasn't a fan of Misono/Lily pair but every pair is in here and has a decent segment on their own. It's done so tastefully and doesn't take away from the story. I've now actually come to love the Lily/Misono pair even! The story has just the right amount of angst and explores BOTH Lily and Misono's pasts to a satisfactory point and doesn't leave you with more questions and gaps as a lot of manga-based movies can. It's really done great given the time constrains too (59 mins including credits and extra scene). I find that a lot of moives-after-season's are just fan-serving and don't add to the stories orare even of decent content but I really have to emphasise that it does tie into the actual series well. I can only hope for more movies (of longer length too) or even better, a second season! Until then give this a watch! I think this would be a lot more popular if there was a better quality and easily accessible english sub version.