KOI-12 is a Sun-like F-type star (about 1.50 solar masses, 6,635 K, 1.40 solar radii), 399 light-years from Earth. KOI-12 b is a 1.10-Jupiter-mass companion, with an orbital period of 17.9 days, at 0.154 AU from its star, on an eccentric orbit (e ≈ 0.34), discovered in 2015 via transit. Kepler-448 c is a 22.0-Jupiter-mass companion, with an orbital period of 6.84 years, at 4.200 AU from its star, on an eccentric orbit (e ≈ 0.65), discovered in 2017 via transit. Mutual gravitational tugs between the planets can slowly reshape their orbits, preserving clues to the system's assembly.