Naruto looks around the cave more and sees a scroll, with the Kanji of bat on it. Curious he picks it up and opens the smoothe paper to read its a bat summoning contract, only those who were worthy would find the location of this cave he reads. "Hm how am I worthy?" He keeps reading, bats are used for air travel, returning information, sound manipulation, and tracking. Bats are masters of the shadows, they only strike when their prey is disoriented with fear.
Naruto spends a hour reading the scrolls content, learning of all bat species he could summon, their sage mode ability, their rarity, intelligence their jutsu library he could learn later. After he was done, he frowned, realizing he could only have one summoning contract, he made the choice and summoned Gamakichi, the little toad confused looks to his summoner Naruto and smiles.
"Hey Naruto, what's up, why are we in a cave?" He stops talking when he sees Narutos grim face, "Gamakichi, I'm sorry to say but because of Jiraiyas passing, my affiliation to Konoha is broken, I must relieve myself from the toad contract." Naruto says to the toad who looks upset but knods in affirmation. "I understand Naruto, pops will be upset to lose such a great summoner, especially after Jiraiya-samas passing, but he'll understand. Take care Naruto I'll miss you." Naruto smiled and waves as the toad poofs back to his realm.
Ok time to become a bat summoner, he bites his thumb, and writes his name in blood, afterwards he does the hand signs and channels chakra in his hands yelling SUMMONING JUSTU, a poof is heard and a small grey vampire bat is seen hanging on narutos finger, The bat looks up and swings back and forth excitingly then says in a high pitch voice "A NEW SUMMONER OH MY KAMI, WE HAVENT HAD ONE IN YEARS..AND HE IS WORTHY." The bat looks up at naruto, and Naruto looks amused "hi my name is Naruto Uzumaki and your newest summoner." The bat squeaks in joy "DON'T WORRY I'LL TELL OUR LADY RIGHT AWAY, FEEL FREE TO SUMMON US ANYTIME NARUTO-SAMA!!"" The bat poofs out of existence leaving a flabbergasted Naruto.
"Well, the bats seem fun. Welp I should get out of this cave, knowing Shikamaru he is probably even more worried then before." Raising the rasengan high, he builds chakra to his feet to climb back up. After a few minutes he reaches the hole he fell through and comes face to face with a relieved Shikamaru. "Oh you scared me Naruto, why do you have to be so troublesome?" The lazy Nara asks.
Rubbing his neck sheepishly Naruto smiles and says "I apologize for not being fully aware of My surroundings, heh let's go back to the camp I'm exhausted." Shikamaru knods and both boys walk back to their camp, the young Uzumaki planning on telling his comrade what happened while he was in the cave the next day.
[A filler episode, that follows my version of Canon Btw I need help naming the bats
There are gonna be the main ones. The female vampire bat the excited one. The flying fox bat a respectful gentleman, the big bat boss she is a lady, then random names for extras. Please if you want to give me some ideas