Formed mainly by students under the Hong Kong national security law in 2020, the group called for continuation of protests to "liberate the city".

On 5 May 2021, four students (Lai Chun-hei, Yuen Ka-him, Chan Ching-hing, Choi Wing-kit) were reportedly arrested on location after sneaking into Po Leung Kuk Laws Foundation College, a secondary school in Tseung Kwan O.

[3][4] Police, during the search, discovered some suspects belonged to Returning Valiant and hid independence slogans and banners at home, including former spokesman Yuen Ka-him.

The NSD said the arrested had attempted to plant car bombs, attack cross-harbour tunnels, railways, court buildings, and public facilities across the city, using TATP; in a raid at a hostel in Tsim Sha Tsui, police had confiscated laboratory equipment for making that highly explosive substance.

[6] Three (Ho Yu-wang, Alexander Au Man, Chan Cheuk-hin) were charged, brought to court, and denied bail on 7 July.

[17] On 8 October 2022, five young defendants, including four minors, were sentenced to up to three years at the training centre by Kwok Wai-kin, national security judge.

[13] Kwok said that "Even if one person is incited, Hong Kong's stability and residents' safety could have been greatly harmed",[19] and claimed that their message could have turned peaceful protestors violent, even though he agreed there was no direct evidence of anyone doing that.

[2][20] On 9 February 2023, Choi Wing-kit, founder of Returning Valiant who faced additional charge of possessing offensive weapons, and Chan Yau-tsun were sentenced to jail.