  We prove that a subspace of a real JBW$^*$-triple is an $M$-summand if and
only if it is a weak$^*$-closed triple ideal. As a consequence, $M$-ideals of
real JB$^*$-triples correspond to norm-closed triple ideals. As in the setting
of complex JB$^*$-triples, a geometric property is characterized in purely
algebraic terms. This is a newfangled treatment of the classical notion of
$M$-ideal in the real setting by a fully new approach due to the unfeasibility
of the known arguments in the setting of complex C$^*$-algebras and
JB$^*$-triples. The results in this note also provide a full characterization
of all $M$-ideals in real C$^*$-algebras, real JB$^*$-algebras and real TROs.
