“Waterfall training’s second nature to me, Shuten. C’mon, let’s see who’s tougher and squeals first.”
“I, too, was raised in a temple… and you’re the last person I want to lose to, Oniwaka! Show me what an ogre’s made of!”

Oniwaka and Shuten, two men found by a temple, raised by a temple, and seen off by a temple. Their near-identical backgrounds have granted them an affinity for each other as well as spawned a fierce rivalry between them. After all, Oniwaka serves descendants of the noble clan which invaded Shuten’s territory, making him one of the few people Shuten will bare his emotions to. Shuten even sees his own childhood memories in Oniwaka. Now, the two meditate under waterfalls together, much like they did in their days of spiritual training at the temple growing up. In a decidedly un-zen-like twist, however, the two are competing in their enlightenment as they each try to outdo the other. Both have the guts to stand proud in the midst of a rain of arrows and have their heads severed off while still biting at their foes. Either would cling to stubborn pride in the face of certain death, proving, though they would be loath to admit it, that they bear a distressing resemblance to each other at the core.

「滝行なんぞは慣れた物だぜ、どっちが先に根を上げるか勝負と行こうじゃねえか、シュテン！」
「儂も同じ寺育ち……お前にだけは負けられへんわ。鬼の根性、その眼で見さらせ、オニワカよう！」
ともに寺に拾われ、寺に育ち、寺を去ることとなったオニワカとシュテン。
その境遇故にお互い親近感と、そしてそれ以上の対抗心を抱く間柄。
オニワカは、シュテンの根城に攻め入った「源たる者」の末裔に仕えているからだ。
シュテンが珍しく、その感情を剥き出しにする数少ない相手の１人であり、そして幼き日々の思い出を重ねる相手でもある。
寺に預けられた懐かしき修行の日々の如く、精神修養の滝行にて２人はムキになって競い合う。
矢の雨の中でも仁王立ち、首だけになったとしても相手に喰らいつくそのド根性。
決死の場面でも意地を張る、そんな彼らの根っこは存外似ているのかもしれない。

「瀑布修行算什麼，我們來比比看誰能撐最久吧，酒吞！」
「我也是在寺廟長大的……可不能輸給你。你就用那雙眼睛好好看清楚鬼的毅力，鬼若！」

同樣被寺廟收養、在寺廟長大，最終也都選擇離開寺廟的鬼若與酒吞。因為相似的境遇，他們之間既有親近感，又存在著超越親近感的競爭心。鬼若侍奉的是攻入酒吞根據地的「起源者」後裔。他是酒吞少數幾個會表露情感的對象之一，也是能讓酒吞回憶起童年時光的人。 就如同在寺廟中那些充滿感懷的修行日子一樣，兩人為了修養精神的瀑布修行而較勁。即使在箭雨中，也要不動聲色地站穩腳步；即使只剩下一顆頭，也要咬住對手，展現堅韌不拔的毅力。即使面對生死攸關的場面，也要堅持到底。或許，他們的本性出乎意料地相似。

“瀑布修行什么的已经习以为常了，来比一比吧，看谁先告饶，酒吞！”
“我也是在寺庙长大的……我不能输给你。让你见识一下鬼的毅力，鬼若！”

鬼若和酒吞都是由寺庙收养，在寺庙长大，又都离开了寺庙。这样的境遇之中，彼此之间产生了一种亲近感，同时也抱有更强烈的竞争心理。因为，鬼若侍奉的是攻入酒吞根据地的“起源者”的后裔。是让酒吞能回忆起其童年生活的回忆，也是酒吞是为数不多能袒露内心情感的对象。在修练精神的瀑布中，两人认真比试了起来，一如栖身寺庙时那些令人怀念的修行日子。那股子倔脾气，身处箭雨之中仍然屹立不倒，即便只剩下首级也会咬住对手。就算决一死战的场面也要坚持己见，在这一点上，他们的本性说不定存在着意外的相似之处。