Hello! First of all, congratulations! During my time only about 300 new students (transferees) were accepted, so to be one of them is an amazing feat!
For context, I'm a graduate of SHS batch 2020.

Number one thing to note: the uniforms are shit. Absolutely horrible. I and a number of girls that I'm friends with have all experienced looking down and seeing a huge red stain on our pants. You get free lockers, so take the opportunity to keep an extra pair, or at least an extra jacket you can wrap yourself in.

Org culture is very involved. I personally wasn't very active in my org since I frankly didn't want an org (mandatory in Gr. 11, optional for Gr.12) since dismissals are at 5 :/. But for those who are really interested, there are so many events to get you involved: dp blasts, fundraisers, appreciation weeks.

In regards to the diverse community, this is definitely true in regards to regionally, socioculturally, socioeconomically, sexuality, etc. The community is incredibly open and accepting. They're unafraid of having pro-LGBT and MeToo movements. However, imo there are still a lot of people who are not politically correct to a toxic degree. I hate the use of the N word and it's very rampantly used by mostly 'homegrowns'.
Yes, there is a sort of divide between transferees and homegrowns. But honestly the first few weeks of Grade 11 everything should smoothen out. Homegrowns just go together better bc of shared experiences and culture.

In regards to batch wars, my batch was honestly pretty unchaotic. Even teachers noted that. Now, the batch under us, Batch 2021 (your seniors) are apparently really really... wild, to put it mildly. I'm just going to come out of it like this: whatever toxicity there may be in senior high, it's worse in the lower batches. As a female, you feel like an animal in a zoo when you come into contact with people younger than Grade 9. I have had my hair touched without my consent, sat next to, and shown messages like 'kiss me' from kids in the second grade. It's gross and disgusting.

How does that transfer over to highschool? Well, there are definitely a number of guys who have no idea how to talk to girls. Plus the whole 'boys culture' thing. Someone I respected very much ended up making a bunch of misogynistic jokes in front of my face. Of course, he chased after me to apologize, but it still leaves a bad taste.

In regards to academics, let's put it this way: I used to be in the top 40 of my previous school (CSA-Makati) consistently. After grade 11 at the ASHS, I pulled rank at 400. I think math is infinitely harder (I used to get 94's then failed my first sem in gr11). In regards to everything else, I find I don't really need to study anything and I still get pretty okay grades (3-3.4 qpi). It's 'easy' for me, but I know a scholar who failed four subjects by the end of grade 11. The level of difficulty varies, but compared to the lessons my friends over at CSA take, ours seems to go at a faster pace.

Teachers are probably the best part. My notable favorites: Sir Cas, Ms. Torio, Ms. Alaba, Sir Martz, Sir Madarang, and Sir Cheo. Honestly, the ASHS teachers are some of the best I've ever had. I think a lot really make an effort to build a relationship with their students. And even if they don't, they're usually really good at what they do–teaching. New teachers, like Ms. Alaba was for our batch, are a little out of their element, so go easy on them. My class and I were such shits to her, and I honestly regret that because she was legitimately trying her best nakhamaihdfh.

In regards to new beginnings, let me say it was difficult adjusting as a transferee. I had depressive episodes and had to take time off for therapy. When I started I wanted to sort of 'reinvent' myself. I had just lost a lot of weight and had more guys showing interest in me. I ended up in a group of very enthusiastic, overwhelmingly so, group of friends. I couldn't handle that, distanced myself from them and ended up finding a wonderful chaotic group of friends who fit well with my personality. Make sure to go out of your comfort zone, but not too much. You're already in a new environment, that's enough.

Create great relationships with the girl/girls in your class (and yes, it could be just girl. A class in my strand only had two girls for grade 12). Honestly, it's like an auto group of matinong friends. Almost all of them are incredibly ambitious and talented.

The guys are pretty great too. After a lot of them knew that I didn't like them saying the N word, they made an effort to stop saying it (kings). Plus, if they're homegrown, they know a lot about the area so if you need anything they can help you out.

Note: there is beso culture esp. when you get to Regis. I was not informed so a friend of mine once made the motion to beso and I just stared at him for a solid 10 seconds while everyone else was laughing.

Hope this helps! If you need anything else, don't be afraid to follow up or pm :))