I don't think I got this, definetly didn't know this was a thing, how do you get it? Is it just a chance thing with a Hana event of smn?
it's not that rare but bot easy to get (i tried 10 timed and i got 3 with ard) you just need to be Before the war (obviusly xD) and sleep with hanna, you'll have a small chance to get ard when you wake up
