This is a what-if story of Oumi no Umi: Minamo ga Yureru Toki.
What would happen if the protagonist were a court noble and aimed to unify the realm with Nobunaga?
Through the protagonist's eyes, we will witness Nobunaga's Tenka Fubu (unification of the realm by military force).
| Published | Title | # |
|---|---|---|
| 2025/05/18 16:22 | Unrest | 100 |
| 2025/05/18 16:16 | Cleaning up | 99 |
| 2025/05/18 16:14 | political upheaval | 98 |
| 2025/05/18 16:13 | Another reason | 97 |
| 2025/05/18 16:11 | Night Battle | 96 |
| 2025/05/18 16:08 | Invitation | 95 |
| 2025/05/18 16:05 | Unrivaled | 94 |
| 2025/05/18 15:58 | reason | 93 |
| 2025/05/18 15:56 | Battle of Kumeda | 92 |
| 2025/01/21 13:54 | greeting | 91 |
In 1550, the Kutsuki clan faces a succession crisis when the Shogun, Ashikaga Yoshifuji (later Yoshiteru), bypasses the rightful heir, the 2-year-old Kutsuki Takewakamaru, in favor of his uncle, Nagatomori. Takewakamaru, a reincarnated individual with 21st-century knowledge, pragmatically accepts this, arguing that the clan, weakened by recent defeat, cannot afford to alienate the Shogun. He advises Nagatomori to leverage the Shogun's "favor" to avoid military demands and even to exploit the Shogun if he seeks refuge. Takewakamaru then moves to Kyoto with his mother, Aya, to live as a Kuge (court noble). He provides Kutsuki with modern innovations like shiitake cultivation, sake, soap, and toothbrushes, securing the clan's prosperity and his own financial independence in exchange for a share of the profits. His grandfather, Kutsuki Tanetsuna, is saddened by Takewakamaru's sacrifice but recognizes his extraordinary genius.
Three years later, Takewakamaru, now nine, resides with his maternal Asukai family in Kyoto. His mother has remarried into the Jimyoin family. The powerful warlord Miyoshi Nagayoshi, in conflict with the Shogun, demands Takewakamaru as a hostage to pressure Kutsuki. Takewakamaru insists on meeting Nagayoshi directly. In a tense encounter, Takewakamaru disarms Nagayoshi by challenging the concept of "gekoku-jo" (overthrowing superiors) and offers strategic advice. He suggests isolating the Shogun in Kutsuki rather than deposing him, thereby eroding Ashikaga influence in Kyoto while Miyoshi solidifies control. He also proposes humiliating traditional powerful families to assert Miyoshi's dominance. Nagayoshi, initially terrified and angered by Takewakamaru's insight, recognizes his genius and asks him to "witness his life." Takewakamaru declines to serve Nagayoshi, prioritizing his mother's peace and his own survival as a Kuge.
Despite Miyoshi Nagayoshi's great-uncle, Sonshiro, advocating for Takewakamaru's elimination, Nagayoshi protects him. Takewakamaru's maternal aunt, Meme Tenji, arranges for him to live in the Imperial Palace for safety, becoming his foster mother. She and his foster father, Asukai Masaharu, observe Takewakamaru's lack of childlike joy and his deep desire to "test his power," committing to support him. Takewakamaru undergoes his coming-of-age ceremony, adopting the name Asukai Mototsuna, and begins training with the renowned sword master Yoshioka Mataichiro Naomoto.
As the Emperor falls gravely ill, the Imperial Court faces a severe financial crisis for funeral and enthronement ceremonies. Mototsuna devises a risky plan to secure funding from Miyoshi Nagayoshi, which would solidify Miyoshi's influence but also risk war. He advises Kutsuki Tanetsuna *not* to provide funds, as it would make Kutsuki a target and strengthen the Shogun's influence. Nagayoshi, having tested various factions' loyalty regarding the Shogun's potential deposition, decides to attack Tanba to weaken his rival, Hosokawa Harumoto, while the Shogun remains isolated in Kutsuki. Mototsuna also establishes a trade and intelligence network using his Kutsuki-produced toothbrushes with a Kyoto merchant, Hazuki.
From the start, Mototsuna is a strategic genius, forced to adapt to a new world. By the end, he has navigated political dangers, gained powerful allies and rivals, and is actively shaping the future of the Imperial Court and his own destiny, albeit with a growing awareness of the ruthless nature of the Sengoku period.
 | Become a Novelist https://ncode.syosetu.com › ... This is an "if" story based on "Amai no Umi: When the Water Surface Shakes." What would have happened if the protagonist had been a nobleman and had sought to rule the country alongside Nobunaga? We will see Nobunaga's military expansion through the protagonist's eyes... |
 | Corona EX https://to-corona-ex.com › comics Urin, Flying Through Warring States: A Different Version of the Sea of Amai... 1550. The year marked the historic beginning of the collapse of the Muromachi Shogunate, when the Ashikaga Shogunate was exiled to the Miyoshi clan. Takewakamaru (2 years old), the next head of the Kutsuki clan, a small fief in Omi... |
 | TO Books https://www.tobooks.jp › afumi 10 Oct 2025 — [Drama CD included] Iden Amai no Umi ~Urin, Soaring Through the Warring States Period~ Volume 6 Released December 15, 2025 Price: 3,159 yen (tax included) ... Includes online store exclusive bonuses! |
 | Amazon.jp https://www.amazon.co.jp › Iden-... A spin-off of the popular Sengoku survival story "Amai no Umi: When the Water Surface Shakes" is underway! A comic adaptation is also in the works! [Synopsis] 1550. The Ashikaga Shogunate is exiled to the Miyoshi clan, and the Muromachi Shogunate collapses... |
 | TO Books Online Store https://tobooks.shop-pro.jp › ... The fifth installment of the popular Sengoku survival story "Amai no Umi: When the Water Surface Shakes"! About the author: Israfil lives in Chiba Prefecture. His hobbies are reading and watching videos. He loves science fiction and history, and is particularly interested in the Sengoku period... |
 | BookWalker https://bookwalker.jp › ... Summary/Contents... The spin-off of the hugely popular Sengoku survival story originally published on "Let's Become a Novelist" is now being adapted into a comic! Includes a newly written short story and a specially drawn manga by the original author, Israfil! |
 | Wikipedia https://ja.wikipedia.org › wiki › Tan... "Afumi no Umi Minamo ga Yureru Toki" (When the Water Surface Shakes) is a Japanese alternate history science fiction novel by Israfil, in which the protagonist is reincarnated into the past of the world he lived in before his reincarnation, and... |
 | Rakuten Market https://search.rakuten.co.jp › mall When the Water Surface of the Amai Sea Stirs: The Revenge of Mototsuna Kuchiki, the Unlucky Man Hated by the Three Great Heroes, Volume 16 [Includes an exclusive original short story] [E-book] [Israfil]. |
| TO Books Online Store https://tobooks.shop-pro.jp › ... Released on Monday, December 15, 2025! Format: Paperback/Softcover Publisher: TO Books Author: Israfil Illustrations: Aoi Fuuha Manga... |
| Amazon.jp https://www.amazon.co.jp › Urin... Includes a newly written short story and a special manga by author Israfil! [Synopsis] 1550. The Ashikaga Shogunate was exiled to the Miyoshi clan, marking the beginning of the collapse of the Muromachi Shogunate... |