My experiences with meeting famous people in real life are kinda strange. I seem to be very inconsistent in how I handle things. Here's a list of situations that come to mind as far as this goes:
1) Meeting three members of Aikatsu Stars, August 2015, Tokyo
On my first visit to Japan, I was quite fortunate to have timed it to a few weeks before the launch of the new Aikatsu movie. Amusingly (read: tragically), I left Japan a week before it launched in cinemas. Gutted. Anyway, news came in of this event to me while I was staying in Kyoto with two friends. The day of the event, my friends were hiking up Mt. Fuji. So, I did what any good friend would do: leave them to it and go to Tokyo. I got the first Shinkansen train from Kyoto up to Tokyo (discounting the subway prior, the Shinkansen was at 6:14am, so I slept for most of my first ever journey on the Shinkansen, go team!) then made my way to Tokyo Skytree where the event was being held.
On the way there (when I wasn't sleeping on my first ever Shinkansen ride) I was trying to figure out what I was going to say to the members of Aikatsu Stars were I to get to say anything to them. I wasn't sure if I would be able to get a ticket to the thing as they were on sale beforehand, but I would try anyway and get to visually see them if nothing else. So I was using what little Japanese I knew combined with getting some words from Google Translate, then typing out in Google Translate in Japanese and seeing if the result made some sense (I figured just typing English into Google Translate and trying to speak it would just get me into trouble and I wanted to understand what I was saying).
So I arrived, bought a variety of Aikatsu goods, and then three members of Aikatsu Stars (Ruka, Mona and Miki) arrived and did a little speech about the film and that they're honorary shop managers for the day or something. I got told off by someone in the crowd for taking a photo (NO PHOTO) and then wandered around Skytree until my timeslot.
Here's the interesting bit. This is the first time I've met someone famous, let alone someone who is so integrated into my life (music, anime, radio, etc) so, as you can expect, I was a nervous wreck! I got in the queue quite early, and it seems to be an unwritten rule that the old idol fans let the kids go in front of you (which is fair, as making kids queue kinda sucks). This means I was the second person to speak to them in this timeslot. First adult, and only blatant foreigner. No pressure. So I promptly forgot most of what I wanted to say save for "Nice to meet you, I'm Peter and I'm British. Thank you for your singing/music." The amount of time they gave me seemed longer than I was expecting, and ended up saying "thank you" a bunch of times. Maybe they gave me more time cos I'm a foreigner, I dunno. Either way, they were all pretty impressed when I said I was British (I suspect it's not common that there's someone British going to an Aikatsu Stars idol meet and greet). Then I got my poster, and that was it. It wasn't much, but I got to meet them, say thank you (a lot) and got a signed poster. I'd say it was a good day.
I'm hoping next time, I manage an actual conversation, and also I hope Nanase is there. The events I went to the following year (2016) had all seven members in a row and you were kinda funnelled through each one pretty quickly, but these were events with a mini-live concert, so were a bit different. Perhaps they're getting too big (both in numbers and in popularity) to have them on a table for you to chat to for a little bit. I dunno. From what I understand, several of the members are affiliated with DearStage, so they might turn up at the cafes and the like. I only found out about it towards the end of my most recent stay in Japan, so this is something to check out for next time. I could also do with chatting to the various Aikatsu fans on my Twitter timeline to find out where I should go, as I've seen several with signed polaroids of members (particularly Ruka).
2) Meeting Charisma.Com at Hyper Japan, July 2016, London
Charisma.Com is a group I've been into for quite a while, so I made a major effort to get to Hyper Japan to see them. Only a month before going to Actual Japan™, I made my way to London and watched the live performances on both the Friday and the Saturday. The accoustics were awful, the floor was level (so those at the back probably couldn't see anything except for that bit when Itsuka was on a stepladder) but it was a damn good show, full of energy and character. I was also very impressed that the set-list for each show was different, so those seeing them every day got a few songs different each time. Honestly, I feel like they're way too big and professional a group for Hyper Japan, but I'm not sure if we'll see them again in the UK. I'll keep an eye out. Anyway, after the show, they came out for signing autographs. Special thanks to @digikerot for giving me a spare "Shikishi Board" as I left my CDs and vinyl at home (I was really hoping to get them to sign my Charisma.com vinyl, maybe next time). I got to speak with them a bit too, which was cool. They were very down-to-earth and knew a little English, and I knew a little Japanese, which also helped. Of course, I have to ruin everything. Gonchi asked me a question and I was very confused about what was said. Turns out, she was asking if the CD I left at home was OLest, their most recent album at the time. It was, by the way, and this was essentially them asking if I'm an avid fan and importing their music from Japan, which I am lol. Very disappointed in myself for getting confused by this. "OLest" is a strange enough title for an album that I should've recognised it immediately >_<
3) NOT meeting bis at The Deaf Institute, May 2016, Manchester
Sometimes, you just bottle out of something you really wish you did. I've been a fan of bis for quite a few years, although I've not really got all their music yet (more on this shortly). Until comparatively recently, I've been too nervous to go to gigs/concerts/etc on my own, so this was a big deal for me. So I made my way down to Manchester after work and after getting food, etc, I got to The Deaf Institute a fair bit earlier than necessary and found a space in the already very full bar. It was then that I spotted the members of bis at a table on the other side of the room chatting and having drinks. I then promptly spent about half an hour trying to encourage myself to head over and say hello/wish them luck for the show/etc. This is a band I am very fond of and listen to almost every day along with the usual Aikatsu stuff, so yeah, I'm a fan. Of course, I couldn't do it, and instead spoke to the person who sat next to me because there were no empty tables (hello Rachel, I am glad I met you, you're cool).
So then I went to the music hall and watched the three bands playing: iLL, BIG ZERO and bis. Three bands with reckless disrespect for capitalisation. iLL and BIG ZERO I had never heard before this gig, so it was cool hearing something new, and both I bought CDs from. This was a very informal gig and both bands came down to watch bis later on. I ended up chatting to members from both as well, so that was also really cool. bis, on the other hand, mostly played songs I've never heard of before, so that shot my idea of being a "big fan" right down hahaha! Still, this turned out okay with chatting with members from iLL and BIG ZERO, plus a couple of people I met in the bar earlier. Overall, it was a good social experience. Hopefully, if I ever see bis in a pub again, I'll say hi, but I'll probably end up glancing over occasionally and blushing into a pint of dandelion and burdock.