The name Triparshva is derived from the Sanskrit meaning trilateral or facing three ways. It has three movements or sides, each dedicated to a component of jo-ha-kyu - the performance paradigm elaborated by the Noh master Zeami and subsequently applied to other Japanese art forms, notably, in the case of haikai no renga, by Basho in his refinement of the kasen.

The first side is jo. Its six verses echo the opening of the kasen. Hokku, wakiku and daisan have full scope to unfold and may deal in honorifics if desired. Verse #4 takes the preface quietly forwards. Moon - albeit not autumn - is at the familiar position #5. Verse #6 rounds off the movement at leisure.

The second side is ha. Concluding with a run of autumn verses, and typically featuring autumn moon at the penultimate position, it recalls the second development movement of the kasen. At ten verses it has sufficient space to cope with forceful writing.

Kyu is also familiar. Uncluttered with extraneous obligations, it is long enough to permit a suitable flourish before closing with the ever amenable blossom and the lingering resonance of a classic ageku.

Each movement of the triparshva contains two distinct seasons. Autumn and spring verses appear in groups of two or three. Winter and summer appear singly or in pairs. Seasons do not straddle the boundaries between sides. The distinction between movements is clear cut.

Of the two moon verses, one is always autumn - normally that of #15 - whilst the other takes a different season. However, for sequences begun in autumn, the moon at #5 may be brought forward to the hokku, in which case - if the other is not also brought forward from #15 - both may be set in autumn.

Sequences begun in spring may have blossom in the hokku as well as at the close. In all cases, though blossom is generally treated as cherry or plum, other flowering and fruiting deciduous trees may feature - including those that are used for hedging. In so far as some flower relatively late, care must be taken to avoid anachronism in the overall run of verses (see The Seasons of Renku).

Love takes two or three verses towards the middle of the development movement. Treated freely or formally, this number may extend to four if koi no yobidashi and/or koi banare are involved (see The Kasen, A Description).

It is difficult to offer a critical appraisal of something which is to all intents and purposes flawless. But the triparshva is the result of human ingenuity, so defects there must be. Perhaps if I were to split my personality...

It looks strange... Having abandoned the polite fiction that it is recorded on conventional writing sheets, the poem does divide into three not four. But of course this number makes complete sense in respect of jo-ha-kyu.

Its proportions are lopsided. Whoever heard of 6/10/6?... Except that the doubling of size between preface and development is no magic bullet in itself. Consider the 4:8 ratio of the tankako. Eight verses are ok for a development movement, especially where there is a second one to follow. But four is tight for the preface or finale (see The Tankako, An Appraisal). And that 6:12 ratio, made so famous by the kasen, is itself a lopsided adjustment from the mediaeval hyakuin's 8:14. The strength of the triparshva is that the movements are optimised. The shape is a function of that.

Well the seasons follow the calendar then... No they don't. In some parts of some distributions, if you choose certain options, you may end up with calendar order. But there are always sufficient miscellaneous verses to make this a tractable problem at worst, and, if you want to avoid the whole issue in the first place, just choose other options.

It's a funny name. Foreign. It's enough to put me off... Yes. That would appear to true for some people. Perhaps if it was called the sanmen - three facets - it would achieve an even greater diffusion. The triparshva is a relatively recent proposal. It has met with almost universal acclaim. At the time of writing, good quality examples have been published in something like a dozen languages. Japanese is not amongst them.

There is no absolute reason why the wish to spread knowledge of renku should imply a commensurate willingness to receive it. But this is a shame as the triparshva has achieved the holy grail. It permits the full exercise of the Basho style in only 22 verses. Funny name or not.