I just started my manga collection this year and it is so hard to find the specific manga that I'm looking for (not some Fairy Tail or Naruto or Bleach). I'll provide some options for this question but if someone can tell me which shop is the most reliable for you to buy your manga. Note that these are physical stores from which you can buy your manga according to the internet. Also, these stores are more or less in Metro Manila.

Fully Booked

I'm glad that they are finally expanding their manga sections and adding new stuff to their stock. I've tried to reserve Nichijou and The Gods Lie online and transfer it to a branch near me. For me, this works well except that sometimes they don't reply that fast (expect reply from them about 3 days after you've filed your reservation) and transfers takes about a week (as compared to 2-3 days according to their website).

Filbar's

This comic shop provides action figures and DC/Marvel comics but they also have a manga section. I've only checked their SM Megamall branch and they have Food Wars, Naruto, Tokyo Ghoul, Bleach, Gyo, and Uzumaki. Someone just bought their Assassination Classroom stock, I think.

National Bookstore

This is where you get all your Attack on Titan, Naruto, and Fairy Tail volumes. Sometimes they would also have Pokemon and Doraemon.

Powerbooks

It has a decent amount of manga but I'm not a fan of their collection. They have more or less the same stock that of the NBS'.

Comic Odyssey

This morning, I went to their Robinsons Galleria branch and it was heaven. They have a LOT of titles, waaaay more titles than Fully Booked. But as of that moment they don't have a complete volumes of a title. They also have local comics and DC/Marvel titles.

I've gathered the following information on where you can buy manga online. I haven't visited the following stores and I would appreciate it if you could comment on their service.

Planet X Comics

Bibliarch

Sketchbooks

Have you bought a manga from these stores? What titles did you find in their shelves? Do they have an online reservation service? Comment below!

Thank you for those who have followed me (after that "review" of Taboo-Tattoo wow)! I might write a very short, concise, easy-to-digest, numbered form review of 91 Days and Shokugeki no Soma: Ni no Sara. If I have time, I might have a flashback blog on some past series.