[5] He made his competitive debut for the club on 18 February, in the main domestic cup Svenska Cupen, providing an assist to Mats Solhem in a 3-0 win against Varbergs BoIS.

[6] Kossounou went on to make nine league appearances in Allsvenskan for the club, most notably being voted man of the match in a 2–2 home draw against IFK Norrköping.

[7] On 8 May 2019, Hammarby reached an agreement with Belgian side Club Brugge for the transfer of Kossonou, effective on 1 July the same year.

[11] On 22 July 2021, Kossounou joined Bundesliga club Bayer Leverkusen on a five-year deal for a reported €23 million fee.

[18] In 2020, Kossounou was the subject of a TV-documentary on Swedish television titled "Det vackra spelet" (The beautiful game), that for three years followed him on his transfer to Hammarby and then on to Club Brugge.