Boku no Tsugai wa Neko Shinshi: Eikoku-hen

Some time after Toushirou, an omega used to harsh treatment due to his rare sexual traits, became mated to Alex, a diplomat from a nation of catlike beast folk, a letter arrives from Alex's family in London. Alex's father, the Nyartigian ambassador to the United Kingdom, summons him to London under the guise of business Alex needs to attend to, although it is a thinly veiled excuse to meet his son's mate.

However, when the couple arrives in London, they are shocked to hear that Alex's family strongly disapproves of their union, even believing that Toushirou should be sequestered in a protective facility for omegas. Unwilling to accept this, Alex tries to reason with his family, all while Toushirou is kept in a private room, alone. As Toushirou begins to question whether he is worthy of being in Alex's life, societal pressures and Alex's sordid past threaten to rip them apart for good.