The Tenryū-class vessels, termed "small-model" (or "3,500-Ton") cruisers, were designed as fast flotilla leaders for the Imperial Navy's new first- and second-class destroyers.

The following year, Tenryū was assigned to patrols of the east coast of Russia, providing support to Japanese troops in the Siberian Intervention against the Bolshevik Red Army.

From 1 December 1928, she was assigned back to Kure, serving as a training vessel for the Imperial Japanese Navy Academy and Submarine School.

On 9 October 1931, Tenryū was assigned to patrols of the Yangtze River in China as part of the IJN 3rd Fleet, and was thus in combat during the January 28 Incident at Shanghai in 1932.

As a component of the IJN 5th Fleet, on 10 May 1938 she covered the landing of Japanese forces at Amoy and on 1 July 1938 supported operations in Guangzhou.

[4] From 1 December 1939, Tenryū was based at Maizuru Naval District as a guard ship and training vessel for the Imperial Japanese Navy Engineering Academy.

[4] During a refit at Truk on 23 February, two additional Type 96 twin-mount 25 mm AA guns were installed aft, as part of the heightened awareness of the threat posed by American aircraft.

[4] Tatsuta and Tenryū were both assigned to the aborted "Operation Mo" (the occupation of Port Moresby, and covered the establishment of a seaplane base at Rekata Bay at Santa Isabel Island from 3–5 May.

The operation was cancelled following the Battle of the Coral Sea, and Tatsuta was recalled to Maizuru Naval Arsenal in Japan for repairs on 24 May, remaining for a month.

The invasion force was attacked by USAAF Boeing B-17 Flying Fortress and Martin B-26 Marauder bombers on its return to Rabaul, but Tenryū was unharmed.

[2] On 9 August 1942, Tenryū was in the Battle of Savo Island, together with the cruisers Yūbari, Aoba, Kako, Kinugasa, Furutaka, and Chōkai, and the destroyer Yūnagi, which attacked US Task Group 62.6 that was screening transports with Allied invasion forces for Guadalcanal.

Tenryū was then tasked with Tokyo Express transport runs from Rabaul to Tassafaronga, Guadalcanal, through early November, evacuating 190 members of the Sasebo No.5 Special Night Operations Landing Force on 26 October[5] and narrowly escaping a torpedo launched by USS Plunger on 3 November off Santa Isabel Island.

[4] The following day, as Tenryū was departing, it was attacked by the submarine USS Albacore, which fired three torpedoes each at a transport and what it identified as a destroyer.