Senku, Taiju and Yuzuriha head to Hakone to collect sulfur for gunpowder, which they’ll need to fight Tsukasa. They accidentally set off an explosion, which attracts some unexpected attention.
To be on the safe side.
.تحسّبًا فحسب
Um auf Nummer sicher zu gehen.
Por si acaso.
Por si acaso.
par précaution.
Come misura di sicurezza.
Por segurança.
Так, на всякий случай.