I don't know what to say, because I don't know how far you are in both Sicae and MBML. But MBML's story comes after Sicae's story.
There's things in the story that point to this, and I can go into more detail if necessary, but the key thing is to look at Kei's (Sicae MC) appearance in Sicae and compare it to his appearance in MBML. You'll notice some strange differences that aren't there at the beginning of MBML. Which instantly puts MBML further in the timeline than Sicae.