Welcome to this 100% completion guide for Highschool Romance!
Before I begin, let me emphasise that this is a guide for those who want to complete the game 100%. The game is pretty easy to complete without a guide so honestly, I reccomend you play the game blind for your first run then return to this guide if you need any direction to get any specific endings.
We'll be going over each of the main endings and detailing how to get every single CG in the game.
There are eighteen CGs overall in the game and while most of them are literally impossible to miss, some are very easy to miss so while it's not too hard to figure out exactly what to do, I thought a guide would be a handy resource for those who needed it.
You can do the endings in any order, but personally I think it might be best if you went for Selina's ending first, then Lea's and then finish off with Hoshi. As such we'll be tackling the endings in this order and counting each CG as we go along.
Also, there's only one achievement not connected to an ending, but I think it's almost impossible to miss but i'll point out how to get it anyway.
That's it for the intro, so let's get stuck in!

So first up is Selina. This is personally my second favorite route, but we're starting with her because... I don't really know.

So here are the choices you need to make, a few don't actually make a difference, but we'll deal with those as they come up.

-I'll do what I have to.
-Unlock CG Number 5! (1 out of 18)
-Try on the clothes.
-Unlock CG Number 4! (2 out of 18, although you only see the sports bra CG, this also unlocks the white bra CG too)
-Leave her to it.
-Go Running
-Unlock CG Number 7! (3 out of 18)
-Try to Win.
-Unlock CG Number 9! (4 out of 18)
-Stop and Help.
-Help Selina (Do this for all four of the festival events, the outcome will be the same but it swings more points in your favor.)
-No. (Honestly it doesn't matter what you say here, since either way you have to go with Hoshi so really you can say whatever you like.)
-Temple (Same as above, but temple is the shorter scene)
-Pop Music (Same as before)
-Unlock CG Number 13! (5 out of 18)
-Say Nothing.
-Unlock CG Number 12! (6 out of 18)
-Selina.
-Let it be. (I don't think this really matters but to keep things short you can just skip the apology)
-Selina.
-Unlock CG Number 16! (7 out of 18)
-Achievement Unlocked! Selina True Love! (1 out of 4)

And that's it for Selina's ending! Going through her story nets you 7 CGs in all and probably my favorite of the ending CGs along with her ending achievement. Next up is Lea's ending!

Time for Lea, the school principal! This is my favorite route personally and has a tricky CG that's a little easy to miss. It's also the location of the game's only non ending related Achievement. So let's get down to business.

-I'll do what I have to.
-Only if you do first.
-Unlock CG Number 1! (8 out of 18)
-Unlock CG Number 2! (9 out of 18)
-Unlock CG Number 3! (10 out of 18)
-Unlock CG Number 6! (11 out of 18)
-Leave her to it/Help Hoshi (This is really down to personal preference since either way you'll be hanging out with Hoshi or Selina so just choose whatever.)
-Go Running (Again, you can play tennis if you like, but Running offers the quickest route out especially if you've already done Selina's Ending)
-Let her win. (Personal preference again, but it's quicker if you just let her win.)
-Risque Underwear (Important! ff you don't pick this you'll miss out on that bonus achievement.)
-Cough (Again, important, otherwise you'll miss out.)
-Unlock CG Number 10! (12 out of 18)
-Achievement Unlocked! Lea Kiss! (2 out of 4)
-Finish the Race. (Again, personal preference really but just finishing the race makes the whole thing go by quicker.)
-Help Hoshi/Help Selina. (Completely dependant on personal preference. So go with whoever you want!)
-Sure, i'd be glad to go!
-It's very nice.
-Yes/No. (Again, personal preference since you really don't have a choice in the matter.)
-Temple (Personal preference, but again, Temple goes by so much quicker, especially if you've been following this guide.)
-Pop Music. (See above.)
-Admit the Truth. (I really don't think this matters but Admitting the Truth works out faster.)
-I'm still interested.
-Unlock CG Number 15! (13 out of 18)
-Pervy
-Show me how
-Selina/Hoshi (Personal preference again, just go with whoever you want!)
-Approach Selina/Leave her Alone (Personal pref again!)
-Lea.
-Unlock CG Number 18! (14 out of 18)
-Achievement Unlocked! Lea True Love! (3 out of 4)

And that's Lea's Route in full! Now we've got another seven CGs under our belt and the majority of the achievements, let's play cleanup and go for our final ending, Hoshi!

Finally, let's get down to Hoshi's ending. While she's perhaps my least favorite, it's still a pretty nice route with some good CGs. It also has two very easy to miss CGs. Let's get to it!

-Heck no!
-Unlock CG Number 14! (15 out of 18)
-I lost mine.
-Help Hoshi.
-Play Tennis.
-Unlock CG Number 8! (16 out of 18)
-Invite Hoshi to karaoke.
-Sexy Bra.
-Unlock CG Number 11! (17 out of 18)
-Finish the Race.
-Help Hoshi. (Do this for all four festival days, you'll get the same outcome as Selina but it wins you some points.)
-Yes. (You can pick no, technically, but just pick Yes.)
-Park.
-Classical.
-Admit the Truth/Say Nothing. (Doesn't really matter which honestly.)
-Hoshi.
-Leave Selina alone. (You can technically apologise but it doesn't matter by this point really so.)
-Hoshi.
-Unlock CG Number 17! (18 out of 18!!!)
-All CGs Unlocked!
-Achievment Unlocked! Hoshi True Love! (4 out of 4!!!)
-All Achievements Unlocked!
-Congrats! You've 100% completed Highschool Romance!

And that's that! Hope you've found this guide useful, feel free to leave a comment if you feel I missed anything or want to add anything.

I'd like to thank AJTilley.Com for making this game, since it's a cute, fluffy dating sim and I really enjoyed it a lot. Here's hoping there's more to come in the future!