Deep Floors Survival (深層サバイバル) is a special short story given to those who purchased volume 14 of DanMachi in Animate, Gamers, Toranoana or Melonbooks.
Summary[]
On one occasion, before they reached the spring beneath the Colosseum, Ryuu pointed out to Bell that although they had obtained equipment, items and some food from the dead adventurers they found, they had no water.
After evaluating their options Ryuu got up to look for something with Bell following her. Once they found a room filled with Oozes, a rare monster that was a shapeless liquid mass, Ryuu hurried to kill a blue one and take its remains before leaving. Once they took shelter in a room Ryuu ordered Bell to make a fire, confirming his suspicions. Ryuu planned to boil it and have them drink it to quench their thirst.
Bell objected at first, but gave in when he saw the determination in Ryuu's eyes. Bell gathered some courage and drank it after letting it boil in a bottle for a while. The taste was horrible and it was difficult to swallow because of how viscous it was, leaving Bell coughing and teary-eyed when he was finished, but hydrated.
Bell asked her if she had done that before. Ryuu denied it and explained that a companion of hers had forced her to read documents that mentioned adventurers who had tried doing this and survived. She added that her partner herself seemed to have done it, she had repelled her when she tried to do force her to do it too. After saying that Ryuu narrowed her eyes as if she was reminiscing and commented that, thanks to her wisdom, she had managed to survive.
Ryuu then brought the bottle to her mouth but stopped before her lips touched it. Bell realized that would be an indirect kiss and asked his friend if she was okay. Ryuu noted they were in the Deep Floors and told him to consider their situation. Bell simply apologized upon hearing her scolding. The Elf drank from the bottle as if it was nothing and urged him to continue forward.
Oblivious to the truth, Bell didn't realize how embarrassing that was for Ryuu, who tried to hide her blushing face from him as the boy lent her his shoulder to lean on.