With the deployment of the Imperial Navy into Tau-31, the Shiratsuyu was one of the first vessels to engage combat with the Bretonian Armed Forces. Being one of the older Takeda vessels in the fleet the crew still did an excellent job. The High Command was pleased and forwarded new orders to Hisashi. He should secure the area around the Newcastle Jump Hole and defend it against Bretonian intruders.

Successful with his task Hiashi remained unpleased with his orders and wanted more. And asked the Naval High Command for further orders as this was a insult for his pride and his crew, the Shiratsuyu was sent out in a small Task Force to raid the northern sector of the Leeds system. Returning successful to Kyushu for maintaince and for further orders for the Shiratsuyu and her crew. Reviewed by their success the High command gave the Shiratsuyu the call sign "Haku" which means Warden in Japanese.

Refueled and repaired, ready for new orders the "Haku" was deployed again into Tau-31 to ensure the Empires war efforts, days and weeks of battles followed the crew began to work under harsh circumstances every day. The Bretonian Crown began to hire mercenaries and moved more and more heavy class battleships into Tau-31, both sides suffered losses numbers beyond any imagination. The Crown recruited the Maltesian Navy into their favour to aid them in their war against us. However, without a special task the Haku fought alongside others to secure the bridgehead at the IMG Station "Holman". The Armed Forces counter-attack on Holman was driven back and was overrun by the Imperial Navy Forces in no time. The Imperial Navy began to spread their influence in the system more and more. Until the siege of Planet Harris began, lured into a trap, a minefield placed by Molly mercenaries resulted in heavy losses for the Imperial Navy and the retreat from Planet Harris. However, the Battlegroup suffered heavy losses inside the Minefield, retreat was ordered by the High Command. Heavy damaged and lost within the Ice Clouds of Tau-31 without the ability to move or sent a distress sign the Haku was officialy lost and destroyed. The Crew fought for life for a chance to sent a lifesign to the High Command. Unable to communicate the Haku drifted into the deep Ice Clouds of Tau-31, there was only one chance to survive long enough to be found alive, cryostasis. The crew went into the pods unknowing if they ever will be safed or drift around in Tau-31 Ice Clouds forever. Hisashi was very confident about the fact that they will be found by the Imperial Navy but he did not saw the outcome of the Tau War for the Empire of Kusari. The end of the war was far away and a defeat was not in sight. The Empire would continue their wild and reckless battles with the Armed Forces until the Gallic invasion of the Taus and Bretonias territory. With the reveal of Gallia and their military strenght both sides were overrun and Gallia took a key position in the Tau War, driving both Kusari and Bretonia out of Tau-31.