SCARLET NEXUS

During Yuito’s play through, after Phase 9 is done and you proceed to Standby Phase 9. Arashi will have joined your team.

During Kasane’s play through, it is as soon as Arashi joins the team and you end up in the hideout. That is on Standby Phase 4.

When you are in the hideout, proceed to the gym go in, and to the left of the door (facing back into the living quarters area) will be two holographic posters of Arashi. Just stare at them for several seconds until the achievement unlocks. The angle may also be a bit weird, but my character stood off to the left side of the posters with the camera aimed at the wall, it unlocked after about 5-8 seconds later.

EDIT:
If the issue persists, try to move away the characters from near the wall by giving them a gift specific to them, it’ll move them to their spot in the hideout. I realised I moved Kasane away when I unlocked this, it never popped with her near it. You can probably also teleport out and back in, but it may not guarantee like the gifts will.

In this video guide I will show you how to stop in front of the OSF poster in the hideout. This can be done during Yuito's story during phase 9 when everyone joins the team. Or during Kasane's story during phase 4. Best to be done during the standby phases of each story. Then go into the training room and look on the wall near the targets. There will be a poster of Arashi, just stand there for a bit and look at it. It might take a little bit for the achievement to pop. If it doesn't, just get closer or step back a bit. Eventually it will pop.

When Arashi joins your team there will be a poster of her in the hideout in the gym room. Stand in front of it for a few seconds and this cheevo will pop.

Parmi les Succès/Trophées facile à obtenir dans Scarlet Nexus, vous trouverez celui qui se nomme "Protection !". Pour le débloquer, il vous suffit d'attendre qu'Arashi Spring rejoigne la planque, puis allez-vous placer devant ses affiches dans la salle d'entrainement. Ne vous collez par trop à elles, sinon le Succès/Trophée ne se déverrouille pas, placez-vous donc à environ 1 mètre du banc et patientez simplement.

Among the easy to get achievements/trophies in Scarlet Nexus, you will find the one called "Protect!". To unlock it, you just have to wait for Arashi Spring to join the hideout, then go and stand in front of his posters in the training room. Don't stick too close to them, otherwise the Achievement/Trophy won't unlock, so stand about 1 meter away from the bench and just wait.