I really enjoyed this show! It's really cute and really funny and even had my eyes tearing up in emotion at some points. It's a strange, original concept yet somehow...it works. Each episode shows a new Oniichan Gacha and each one has a different personality or gimmick, so it's fun and amusing to see how the family reacts to them. I'm a big fan of Johnny's Entertainment idols and what initially drew me was all the Johnny's Juniors on the cast list. (So, if you want some nice ikemen eye candy, you'd enjoy this)
However, what kept me watching was the love-hate dynamic between the two main characters, Miko and Toi (played wonderfully by Suzuki Rio and Kishi Yuta; they had excellent chemistry together). Will Toi change his mind about wanting to be Miko's older brother? Will Miko ever find the right Oniichan? I was surprised by how emotionally invested I became.
I recommend giving this show a watch if you want a short, bite-size, 20 min. burst of cuteness, comedy, and pretty boys.