Fuga: Melodies of Steel

Hi tank-trainers,

you will unlock the ability to explore around chapter 2. When you reach this point in the story, the game (as usually) will walk you through the process. In order to unlock this achievement, you will need to go exploring and finish it with a S-rank 10 times. I unlocked it around chapter 5, but it can be done earlier if you need to get this specifically.

You will mostly explore while being on an intermission (ergo not in battle). In order to explore, go up to your tank into the observation room. Pick the option on the right to go on an exploration (left being the "observe"-option, which is linked to another achievement).
You can pick any characters and it will cost you 5 AP. On an exploration, you get ranked for collecting items, killing monsters and opening the treasure. On the level 1 explorations, you will hardly get worst than a S-rank. On Level 2 explorations (which you will unlock later in the story), you might actually fail a S-Rank. Possible mistakes are: not collecting everything, not killing all monsters, falling into traps, etc.

Main advice: go slow (no timer!) and check all rooms before attacking objects/monsters first (ammunition can be tight or linked to specific tasks to continue).

Side note: you could get 4 explorations in each intermission, assuming you want to spend all your AP on this. You will also, depending on the chosen roads in battle, come across a few explorations. These news explorations will then be added to your possible explorations and count towards the achievement (if S-ranked).

Hope this helps. Greetings!